| ||||
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Cardinal | sixty-nine | |||
Ordinal | 69th (sixty-ninth) | |||
Factorization | 3 × 23 | |||
Divisors | 1, 3, 23, 69 | |||
Greek numeral | ΞΘ´ | |||
Roman numeral | LXIX | |||
Binary | 10001012 | |||
Ternary | 21203 | |||
Senary | 1536 | |||
Octal | 1058 | |||
Duodecimal | 5912 | |||
Hexadecimal | 4516 |
69 (sixty-nine) is the natural number following 68 and preceding 70. An odd number and a composite number, 69 is divisible by 1, 3, 23 and 69. 69 is a semiprime because it is a natural number that is the product of exactly two prime numbers (3 and 23), and an interprime between the numbers of 67 and 71. Because 69 is not divisible by any square number other than 1, it is categorised as a square-free integer. 69 is also a Blum integer since the two factors of 69 are both Gaussian primes. In number theory, 69 is a deficient number, arithmetic number and a congruent number.
In reference to 69ing, a sex position in which two partners align themselves to simultaneously achieve oral sex, the number 69 itself has become an Internet meme as an inherently funny number in which users will respond to any occurrence of the number with the word "nice" to draw specific attention to it. Because of its association with the sex position and resulting meme, 69 has been humorously named "the sex number".
69, spelled sixty-nine, is the natural number that follows 68 and precedes 70. [1] [2] An odd number, 69 is divisible by 1, 3, 23 and 69. [3] [4]
69 is a composite number, meaning that it is not a prime, and a lucky number. [5] [6] As a natural number that is the product of exactly two prime numbers (3 and 23), 69 is a semiprime and an interprime between the numbers 67 and 71. [7] [8] The aliquot sum of 69 is 27 within the aliquot sequence (69, 27, 13, 1, 0) and is the third composite number in the 13-aliquot tree, following 27 and 35. [9] Because 69 is not divisible by any square number other than 1, it is categorised as a square-free integer. [10] 69 is also a Blum integer since the two factors of 69 are both Gaussian primes, an Ulam number, and a centered tetrahedral number—a figurate number that represents a pyramid with a triangular base and all other points arranged in layers above the base, forming a tetrahedron shape. [11] [12] [13]
In decimal, 69 is the only natural number whose square (4761) and cube (328509) use every digit from 0–9 exactly once. [14] 69 is equal to 105 octal, while 105 is equal to 69 hexadecimal (this same property can be applied to all numbers from 64 to 69). [15] It is also the largest number whose factorial is less than a googol. On many handheld scientific and graphing calculators, 69! (1.711224524×1098) is the highest factorial that can be calculated due to memory limitations. [16] Visually, 69 is a strobogrammatic number because it looks the same when viewed both right-side and upside down. [17]
In number theory, 69 is a deficient number because the sum of its proper divisors (excluding itself) is less than the number of itself. [18] As an integer for which the arithmetic mean average of its positive divisors is also an integer, 69 is a arithmetic number. [19] 69 is a congruent number—a positive integer that is the area of a right triangle with three rational number sides—and an amenable number because it can be divided evenly by 2. [20] [21] 69 can be expressed as the sum of consecutive positive integers in multiple ways, making it a polite number. [22] 69 is also a pernicious number, because there is a prime number of 1s when it is written as a binary number, and an odious number as it is a positive integer that has an odd number of 1s in its binary expansion. [23] [24]
In chemistry, 69 is the atomic number of thulium, a rare lanthanide (category of metallic elements). [25] In astronomy, the Messier object M69 is a globular cluster in the constellation of Sagittarius; [26] 69 Hesperia is a main-belt asteroid. [27] NGC 69 is the designation given to a barred lenticular galaxy located in the Andromeda constellation. [28] [29] 69 also resembles the symbol for the zodiac sign for Cancer, ♋︎
, and in the Canadian Football League, ineligible receivers wear numbers 50 to 69. [30] [31] In ASCII, 69 is the decimal for the uppercase E character. [32]
69ing is a sex position wherein each partner aligning themselves to simultaneously achieve oral sex with each other. [33] In reference to this sex act, the number 69 itself has become an Internet meme as an inherently funny number in which users will respond to any occurrence of the number with the word "nice" to draw specific attention to it. This means to humorously imply that the reference to the sex position was intentional. Because of its association with the sex position and resulting meme, 69 has been named "the sex number". [34] In music, the American rapper 6ix9ine (pronounced "six nine") chose the stage name in reference to the sex position as well as the yin-yang symbol. [35]
10 (ten) is the even natural number following 9 and preceding 11. Ten is the base of the decimal numeral system, the most common system of denoting numbers in both spoken and written language.
15 (fifteen) is the natural number following 14 and preceding 16.
21 (twenty-one) is the natural number following 20 and preceding 22.
33 (thirty-three) is the natural number following 32 and preceding 34.
90 (ninety) is the natural number following 89 and preceding 91.
38 (thirty-eight) is the natural number following 37 and preceding 39.
35 (thirty-five) is the natural number following 34 and preceding 36.
34 (thirty-four) is the natural number following 33 and preceding 35.
55 (fifty-five) is the natural number following 54 and preceding 56.
57 (fifty-seven) is the natural number following 56 and preceding 58.
58 (fifty-eight) is the natural number following 57 and preceding 59.
64 (sixty-four) is the natural number following 63 and preceding 65.
91 (ninety-one) is the natural number following 90 and preceding 92.
300 is the natural number following 299 and preceding 301.
135 is the natural number following 134 and preceding 136.
177 is the natural number following 176 and preceding 178.
288 is the natural number following 287 and preceding 289. Because 288 = 2 · 12 · 12, it may also be called "two gross" or "two dozen dozen".
744 is the natural number following 743 and preceding 745.
888 is the natural number following 887 and preceding 889.
262 is a natural number preceded by the number 261 and followed by 263. It has the prime factorization 2·131.