42 (number)

For other uses, see 42.

← 41 42 43 →
← 40 41 42 43 44 45 46 47 48 49 → List of numbers Integers ← 0 10 20 30 40 50 60 70 80 90 →
Cardinal	forty-two
Ordinal	42nd (forty-second)
Factorization	2 × 3 × 7
Divisors	1, 2, 3, 6, 7, 14, 21, 42
Greek numeral	ΜΒ´
Roman numeral	XLII, xlii
Binary	1010102
Ternary	11203
Senary	1106
Octal	528
Duodecimal	3612
Hexadecimal	2A16

42 (forty-two) is the natural number following 41 and preceding 43.

Mathematics

42 is a pronic number, ^[1] an abundant number ^[2] as well as a highly abundant number, ^[3] a sphenic number, a practical number, ^[4] and a Catalan number. ^[5]

The 42-sided tetracontadigon is the largest such regular polygon that can only tile a vertex alongside other regular polygons, without tiling the plane. ^{[6] [7] [8]}

42 is the magic constant of the smallest non-trivial magic cube, a ${\displaystyle 3\times 3\times 3}$ cube with entries of 1 through 27, where every row, column, corridor, and diagonal passing through the center sums to forty-two. ^{[9] [10]}

42 can be expressed as the sum of three cubes: (80,435,758,145,817,515)³ + (12,602,123,297,335,631)³ + (-80,538,738,812,075,974)³ . ^[11]

The 3×3×3 simple magic cube with rows summing to 42

Wisdom literature, religion, and philosophy

• Abrahamic religions
  • 42 is the number with which God creates the Universe in Kabbalistic tradition. In Kabbalah, the most significant name is that of the En Sof (also known as "Ein Sof", "Infinite" or "Endless"), who is above the Sefirot (sometimes spelled "Sephirot"). ^[12] The Forty-Two-Lettered Name contains four combined names which are spelled in Hebrew letters. While there are obvious links between the Forty-Two Lettered Name of the Babylonian Talmud and the Kabbalah's 42 Lettered Name, they are probably not identical because of the Kabbalah's emphasis on numbers. The Kabbalah also contains a 45 Lettered Name and a 72 Lettered Name. ^[13]

Popular culture

The Hitchhiker's Guide to the Galaxy

The Answer to the Ultimate Question of Life, The Universe, and Everything

Main article: Phrases from The Hitchhiker's Guide to the Galaxy § The Answer to the Ultimate Question of Life, the Universe, and Everything is 42

The number 42 is, in The Hitchhiker's Guide to the Galaxy by Douglas Adams, the "Answer to the Ultimate Question of Life, the Universe, and Everything", calculated by an enormous supercomputer named Deep Thought over a period of 7.5 million years. Unfortunately, no one knows what the question is. Thus, to calculate the Ultimate Question, a special computer the size of a small planet was built from organic components and named "Earth". The Ultimate Question "What do you get when you multiply six by nine" ^[14] is found by Arthur Dent and Ford Prefect in the second book of the series, The Restaurant at the End of the Universe . This appeared first in the radio play and later in the novelization of The Hitchhiker's Guide to the Galaxy .

The fourth book in the series, the novel So Long, and Thanks for All the Fish , contains 42 chapters. According to the novel Mostly Harmless , 42 is the street address of Stavromula Beta.

In 1994, Adams created the 42 Puzzle , a game based on the number 42. Adams says he picked the number simply as a joke, with no deeper meaning.

Google also has a calculator easter egg when one searches "the answer to the ultimate question of life, the universe, and everything." Once typed (all in lowercase), the calculator answers with the number 42. ^[15]

Jackie Robinson

Jackie Robinson in his now-retired number 42 jersey

• The jersey number of Jackie Robinson, which is the only number retired by all Major League Baseball teams. Although the number was retired in 1997, Mariano Rivera of the New York Yankees, the last professional baseball player to wear number 42, continued to wear it until he retired at the end of the 2013 season. As of the 2014 season, no player ever again wore the number 42 in Major League Baseball except on Jackie Robinson Day (April 15), when all uniformed personnel (players, managers, coaches, and umpires) wear the number.

Other

In Japanese culture, the number 42 is considered unlucky because the numerals when pronounced separately—shi ni (four two)—sound like the word "dying", ^[16] like the Latin word "mori".

References

1. Sloane, N. J. A. (ed.). "SequenceA002378(Oblong (or promic, pronic, or heteromecic) numbers)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation. Retrieved 2016-05-30.
2. Sloane, N. J. A. (ed.). "SequenceA005101(Abundant numbers (sum of divisors of m exceeds 2m).)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation. Retrieved 2024-01-07.
3. Sloane, N. J. A. (ed.). "SequenceA002093(Highly abundant numbers)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation. Retrieved 2024-11-14.
4. Sloane, N. J. A. (ed.). "SequenceA005153(Practical numbers)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation. Retrieved 2024-11-14.
5. Sloane, N. J. A. (ed.). "SequenceA000108(Catalan numbers)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation. Retrieved 2016-05-30.
6. Grünbaum, Branko; Shepard, Geoffrey (November 1977). "Tilings by Regular Polygons" (PDF). Mathematics Magazine . 50 (5). Taylor & Francis, Ltd.: 229–230. doi:10.2307/2689529. ISSN   0025-570X. JSTOR   2689529. S2CID   123776612. Zbl   0385.51006.
7. Dallas, Elmslie William (1855). "Part II. (VII): Of the Circle, with its Inscribed and Circumscribed Figures − Equal Division and the Construction of Polygons". The Elements of Plane Practical Geometry. London: John W. Parker & Son, West Strand. p. 134.
8. Jardine, Kevin. "Shield - a 3.7.42 tiling". Imperfect Congruence. Retrieved 2023-01-09. 3.7.42 as a unit facet in an irregular tiling.
9. Andrews, William Symes (1960). Magic Squares and Cubes (PDF) (2nd ed.). New York: Dover Publications. p. 65. doi:10.2307/3603128. ISBN   9780486206585. JSTOR   3603128. MR   0114763. OCLC   1136401. S2CID   121770908. Zbl   1003.05500.
10. Sloane, N. J. A. (ed.). "SequenceA027441(a(n) equal to (n^4 + n)/2 (Row sums of an n X n X n magic cube, when it exists).)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation. Retrieved 2024-01-07.
11. Booker, Andrew R.; Sutherland, Andrew V. (2021). "On a question of Mordell". Proceedings of the National Academy of Sciences. 118 (11). arXiv: 2007.01209 . Bibcode:2021PNAS..11822377B. doi: 10.1073/pnas.2022377118 . PMC   7980389 . PMID   33692126.
12. Joel Primack; Nancy E. Abrams. "In A Beginning...Quantum Cosmology and Kabbalah" (PDF). Retrieved 2008-03-14.
13. "The Prayer of the Kabbalist". Archived from the original on 2025-09-18. Retrieved 2025-10-10.
14. "Mathematical Fiction: Hitchhiker's Guide to the Galaxy (1979)" . Retrieved 30 November 2016. See this website for possible explanations of this seeming error.
15. "17 amazing Google Easter eggs". CBS News. November 11, 2011. Retrieved November 1, 2022.
16. Niiya, Brian. Japanese American history: an A-to-Z reference from 1868 to the present. Facts on File, Inc., 1993, p. 352

External links

Media related to 42 (number) at Wikimedia Commons

• Grime, James; Gerardo Adesso; Phil Moriarty. "42 and Douglas Adams". Numberphile. Brady Haran. Archived from the original on 2018-10-13. Retrieved 2013-04-08.
• My latest favorite Number: 42, John C. Baez
• The number Forty-two in real life