Sixtynine

Sixtynine refers to the number 69 written as a single word, a nonstandard variant of the ordinary written form sixty-nine. The standard spelling uses a hyphen.

In mathematics, 69 is an odd composite number. Its prime factorization is 3 × 23; it has divisors 1, 3, 23, 69. In Roman numerals it is LXIX. In binary it is 1000101; in octal it is 105; in hexadecimal it is 45. The number lies between 68 and 70 on the real number line.

In science, 69 is the atomic number of thulium (Tm), a rare earth metal. In astronomy, Messier 69 (M69) is a globular cluster in the constellation Sagittarius.

In culture, the number 69 is widely recognized as a sexual position involving mutual oral sex, and is also associated with the year 1969, a period marked by events such as the Apollo 11 moon landing and Woodstock.

Etymology and usage: The term sixtynine is a concatenation of "sixty" and "nine"; usage as a single word is unusual in formal writing. In computing, 69 is the ASCII code for the letter E, and UDP port 69 is assigned to the Trivial File Transfer Protocol (TFTP).