13 (number)

Last updated

12 13 14
Cardinal thirteen
Ordinal 13th
(thirteenth)
Numeral system tredecimal
Factorization prime
Prime 6th
Divisors 1, 13
Greek numeral ΙΓ´
Roman numeral XIII, xiii
Binary 11012
Ternary 1113
Senary 216
Octal 158
Duodecimal 1112
Hexadecimal D16
Hebrew numeral י"ג
Babylonian numeral 𒌋𒐗

13 (thirteen) is the natural number following 12 and preceding 14.

Contents

Folklore surrounding the number 13 appears in many cultures around the world: one theory is that this is due to the cultures employing lunar-solar calendars (there are approximately 12.41 lunations per solar year, and hence 12 "true months" plus a smaller, and often portentous, thirteenth month). This can be witnessed, for example, in the "Twelve Days of Christmas" of Western European tradition. [1]

In mathematics

The number 13 is a prime number, happy number [2] and a lucky number. [3] It is a twin prime with 11, as well as a cousin prime with 17. It is the second of only 3 Wilson primes: 5, 13, and 563. A 13-sided regular polygon is called a tridecagon.

List of basic calculations

Multiplication 12345678910111213141516171819202122232425501001000
(13)x13 26 39 52 65 78 91 104 117 130 143 156 169 182 195 208 221 234 247 260 273 286 299 312 325 650 1300 13000
Division 123456789101112131415
13 ÷ x136.54.33.252.62.161.8571421.6251.41.31.181.08310.92857140.86
x ÷ 130.0769230.1538460.2307690.3076920.3846150.4615380.5384610.6153840.6923070.7692300.8461530.92307611.0769231.153846
Exponentiation 1234567891011
13x13169219728561371293482680962748517815730721106044993731378584918491792160394037
x13181921594323671088641220703125130606940169688901040754975581388825418658283291000000000000034522712143931

In languages

Grammar

Folklore

In Germany, according to an old tradition, 13 (dreizehn), as the first compound number, was the first number written in digits; the numbers 0 (null) through 12 (zwölf) were spelled out. The Duden (the German standard dictionary) now calls this tradition (which was actually never written down as an official rule) outdated and no longer valid, but many writers still follow it. [4]

In English

Thirteen is one of two numbers within the teen numerical range (13–19), along with fifteen, not derived by cardinal numeral (three) and the teen suffix; instead, it is derived from the ordinal numeral (third).

In religion

Islam

In Shia, 13 signifies the 13th day of the month of Rajab (the Lunar calendar), which is the birth of Imam Ali.

Catholicism

In Catholic devotional practice, the number thirteen is also associated with Saint Anthony of Padua, since his feast day falls on June 13. A traditional devotion called the Thirteen Tuesdays of St. Anthony [5] involves praying to the saint every Tuesday over a period of thirteen weeks. Another devotion, St. Anthony's Chaplet, consists of thirteen decades of three beads each. [6]

Sikhism

According to famous Sakhi (evidence) or the story of Guru Nanak Dev Ji, when he was an accountant at a town of Sultanpur Lodhi, he was distributing groceries to people. When he gave groceries to the 13th person, he stopped because in Gurmukhi and Hindi the word 13 is called terah, which means yours. And Guru Nanak Dev Ji kept saying, "Yours, yours, yours..." remembering God. People reported to the emperor that Guru Nanak Dev Ji was giving out free food to the people. When treasures were checked, there was more money than before.

Judaism

Wicca

A common tradition in the religion Wicca holds that the number of members for a coven is ideally thirteen, though this tradition is not universal. [7]

Luck

Bad

Many buttons (4187599550).jpg
This elevator skips the number 13 and jumps from floor 12 to 14. The thirteenth floor continues to physically exist, but is now represented by the numerical symbols for the number 14.

The number 13 is considered an unlucky number in some countries. [8] The end of the Mayan calendar's 13th Baktun was superstitiously feared as a harbinger of the apocalyptic 2012 phenomenon. [9] Fear of the number 13 has a specifically recognized phobia, triskaidekaphobia, a word first recorded in 1911. [10] The superstitious sufferers of triskaidekaphobia try to avoid bad luck by keeping away from anything numbered or labelled thirteen. As a result, companies and manufacturers use another way of numbering or labelling to avoid the number, with hotels and tall buildings being conspicuous examples (thirteenth floor). [11] It is also considered unlucky to have thirteen guests at a table. Friday the 13th has been considered an unlucky day. [8]

There are a number of theories as to why the number thirteen became associated with bad luck, but none of them have been accepted as likely. [8]

The Last Supper
Jesus Christ's Last Supper, there were thirteen people around the table, counting Christ and the twelve apostles. Some believe this is unlucky because one of those thirteen, Judas Iscariot, was the betrayer of Jesus Christ. From the 1890s, a number of English language sources relate the "unlucky" thirteen to an idea that at the Last Supper, Judas, the disciple who betrayed Jesus, was the 13th to sit at the table. [12]
Knights Templar
On Friday, 13 October 1307, King Philip IV of France ordered the arrest of the Knights Templar, [8] and most of the knights were tortured and killed.
Full moons
A year with 13 full moons instead of 12 posed problems for the monks in charge of the calendars. "This was considered a very unfortunate circumstance, especially by the monks who had charge of the calendar of thirteen months for that year, and it upset the regular arrangement of church festivals. For this reason, thirteen came to be considered an unlucky number." [13] However, a typical century has about 37 years that have 13 full moons, compared to 63 years with 12 full moons, and typically every third or fourth year has 13 full moons. [14]
A suppressed lunar cult
In ancient cultures, the number 13 represented femininity, because it corresponded to the number of lunar (menstrual) cycles in a year (13 × 28 = 364 days). The theory is that, as the solar calendar triumphed over the lunar, the number thirteen became anathema. [8] [15]
Hammurabi's code
There is a myth that the earliest reference to thirteen being unlucky or evil is in the Babylonian Code of Hammurabi (circa 1780 BC), where the thirteenth law is said to be omitted. In fact, the original Code of Hammurabi has no numeration. The translation by L.W. King (1910), edited by Richard Hooker, omitted one article: If the seller have gone to (his) fate (i. e., have died), the purchaser shall recover damages in said case fivefold from the estate of the seller. Other translations of the Code of Hammurabi, for example the translation by Robert Francis Harper, include the 13th article. [16]

Good

Singer Taylor Swift considers the number 13 to be lucky & references throughout her work Taylor Swift (6820736052).jpg
Singer Taylor Swift considers the number 13 to be lucky & references throughout her work

Other

A baker's dozen, devil's dozen, [21] long dozen, or long measure is 13, one more than a standard dozen. The thirteenth loaf is called the vantage loaf because it is considered advantageous overall to get 13 loaves for the price of 12. [22]

In a tarot card deck, XIII is the card of Death, usually picturing the Pale Horse with its rider.

Age 13

History

The Great Seal of the United States features several groupings which consist of 13 things of the same type e.g. 13 olive leaves, 13 stars, 13 arrows. Great Seal of the United States (obverse).svg
The Great Seal of the United States features several groupings which consist of 13 things of the same type e.g. 13 olive leaves, 13 stars, 13 arrows.

In sports

See also

Related Research Articles

<span class="mw-page-title-main">Full moon</span> Lunar phase: completely illuminated disc

The full moon is the lunar phase when the Moon appears fully illuminated from Earth's perspective. This occurs when Earth is located between the Sun and the Moon. This means that the lunar hemisphere facing Earth—the near side—is completely sunlit and appears as an approximately circular disk. The full moon occurs roughly once a month.

<span class="mw-page-title-main">Metonic cycle</span> 19-year pattern in lunisolar calendars

The Metonic cycle or enneadecaeteris is a period of almost exactly 19 years after which the lunar phases recur at the same time of the year. The recurrence is not perfect, and by precise observation the Metonic cycle defined as 235 synodic months is just 2 hours, 4 minutes and 58 seconds longer than 19 tropical years. Meton of Athens, in the 5th century BC, judged the cycle to be a whole number of days, 6,940. Using these whole numbers facilitates the construction of a lunisolar calendar.

<span class="mw-page-title-main">Roman calendar</span> Calendar used by the Roman Kingdom and Roman Republic

The Roman calendar was the calendar used by the Roman Kingdom and Roman Republic. Although the term is primarily used for Rome's pre-Julian calendars, it is often used inclusively of the Julian calendar established by Julius Caesar in 46 BC.

<span class="mw-page-title-main">Triskaidekaphobia</span> Fear of the number 13

Triskaidekaphobia is fear or avoidance of the number 13. It is also a reason for the fear of Friday the 13th, called paraskevidekatriaphobia or friggatriskaidekaphobia.

<span class="mw-page-title-main">Friday the 13th</span> Unlucky day in popular superstition

Friday the 13th is considered an unlucky day in Western superstition. It occurs when the 13th day of the month in the Gregorian calendar falls on a Friday, which happens at least once every year but can occur up to three times in the same year. Common years that begin in Thursday have three Friday the 13ths in February, March, and November, such as 2009, 2015, and 2026. Leap years that begin on Sunday such as 2012 and 2040, also have three Friday the 13ths in January, April, and July. The years 2001, 2002, 2004, 2006, 2007, 2013, 2017, 2018, 2019, 2020, 2023 and 2024 had two Friday the 13ths, as will 2029; 2003, 2005, 2008, 2010, 2011, 2014, 2016, 2021, and 2022 had only one Friday the 13th, as will 2025, 2027, and 2028.

<span class="mw-page-title-main">Egyptian calendar</span> Calendar used in ancient Egypt before 22 BC

The ancient Egyptian calendar – a civil calendar – was a solar calendar with a 365-day year. The year consisted of three seasons of 120 days each, plus an intercalary month of five epagomenal days treated as outside of the year proper. Each season was divided into four months of 30 days. These twelve months were initially numbered within each season but came to also be known by the names of their principal festivals. Each month was divided into three 10-day periods known as decans or decades. It has been suggested that during the Nineteenth Dynasty and the Twentieth Dynasty the last two days of each decan were usually treated as a kind of weekend for the royal craftsmen, with royal artisans free from work.

12 (twelve) is the natural number following 11 and preceding 13.

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<span class="mw-page-title-main">Blue moon</span> Metaphor for a rare event, or lunar calendrical term

A blue moon refers either to the presence of a second full moon in a calendar month, to the third full moon in a season containing four, or to a moon that appears blue due to atmospheric effects.

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<span class="mw-page-title-main">Mesoamerican calendars</span>

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<span class="mw-page-title-main">Tibetan calendar</span> Tibetan Lunisolar calendar

The Tibetan calendar, or the Phukpa calendar, known as the Tibetan lunar calendar, is a lunisolar calendar composed of either 12 or 13 lunar months, each beginning and ending with a new moon. A thirteenth month is added every two or three years, so that an average Tibetan year is equal to the solar year. The 15th century Phukpa calendar is the main Tibetan calendar, and the Karma Kagyu's Tsurluk calendar is also in current use. The Tibetan New Year celebration is Losar, which falls either in the months of February or March in the Gregorian calendar.

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<span class="mw-page-title-main">Yakudoshi</span> Ages traditionally considered unlucky in Japan

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Numerophobia, arithmophobia, or mathematics anxiety is an anxiety disorder, involving fear of dealing with numbers or mathematics. Sometimes numerophobia refers to fear of particular numbers. Some people with this condition may be afraid of even numbers, odd numbers, unlucky numbers, and/or lucky numbers. Those with this phobia may have a hard time holding certain jobs, paying bills, or managing a budget.

References

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  2. "Sloane's A007770 : Happy numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved June 1, 2016.
  3. "A000959 Lucky numbers. (Formerly M2616 N1035)". OEIS: The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved October 31, 2018.
  4. "Duden | Schreibung von Zahlen bis 12". www.duden.de (in German). Retrieved March 23, 2020.
  5. "The Shrine of St. Anthony". shrineofstanthony.org.
  6. "Liturgical Year: Prayers: Chaplet of St. Anthony". catholicculture.org.
  7. Raymond Buckland (1986). Buckland's Complete Book of Witchcraft. St. Paul, MN: Llewellyn. pp. 17–18–53. ISBN   9780875420509 . Retrieved February 17, 2022.
  8. 1 2 3 4 5 Emery, David. "Why Is Friday the 13th Unlucky? - History and Folklore". About.com Entertainment. Archived from the original on January 16, 2017. Retrieved August 1, 2011.
  9. "Most Popular E-mail Newsletter". USA Today. November 24, 2011.
  10. "triskaidekaphobia" . Oxford English Dictionary (Online ed.). Oxford University Press.(Subscription or participating institution membership required.)
  11. Fleischman, Sid (August 19, 2007). "The 13th Floor: A Ghost Story". The Washington Post. Retrieved July 26, 2008.
  12. Cecil Adams (1992-11-06). "Why is the number 13 considered unlucky?". The Straight Dope. Retrieved 2011-05-13.
  13. "The Really Strange Story Behind Sunday's Blue Moon". Space.com. November 19, 2010.
  14. Cooley, Keith (2008). "Full Moons 1900-2100". Johns Hopkins University Applied Physics Laboratory. Archived from the original on June 24, 2011. Retrieved August 1, 2011.
  15. Stan Gooch, Guardians of the Ancient Wisdom (1980)
  16. The Code of Hammurabi (Harper translation)
  17. What Makes Taylor Swift's Lucky Number 13 So Special? See Here;Outlook India; Dec 14, 2023
  18. Owen, Davies (2018). A Supernatural War: Magic, Divination, and Faith During the First World War. Oxford: Oxford University Press. p. 136. ISBN   9780198794554.
  19. "Tredici: Definizione e significato di tredici". dizionari.corriere.it. Dizionario di Italiano il Sabatini Coletti (in Italian). Archived from the original on June 22, 2019.
  20. "Colgate: History & Traditions". Colgate University. Archived from the original on August 14, 2007. Retrieved September 1, 2007.
  21. "Definition of DEVIL'S DOZEN". www.merriam-webster.com. Retrieved May 9, 2022.
  22. "Vantage loaf". Green's Dictionary of Slang. Oxford University Press. 2011. ISBN   978-0-19-982994-1 . Retrieved July 22, 2020.