Sixtyeight

Sixtyeight is the natural number that follows sixty-seven and precedes sixty-nine. The conventional written form in English is sixty-eight, typically hyphenated; sixtyeight without a space or hyphen is nonstandard and mainly appears in stylized or domain-specific contexts.

Mathematically, 68 is an even composite number. Its prime factorization is 2^2 × 17, so its positive divisors are 1, 2, 4, 17, 34, and 68. The sum of all divisors is 126, which makes 68 a deficient number since the sum of its proper divisors (126 − 68 = 58) is less than 68. In various base representations, 68 equals 68 in decimal, 44 in hexadecimal, 104 in octal, and 1000100 in binary. In Roman numerals it is LXVIII.

In science, the atomic number of erbium is 68, and the element symbol is Er. Erbium is a lanthanide used in applications such as fiber-optic communications, solid-state lasers, and certain alloy and dopant technologies.

Culturally and historically, the figure 68 appears in discussions of numbers and sequences, and the year 1968 is often noted for significant social and political events in many countries. In mathematics and science contexts, 68 serves as a representative example of an even composite number with a straightforward prime factorization and common numeral representations.

Overall, sixtyeight denotes the integer 68 across mathematics, science, and everyday notation, with its standard written form sixty-eight and its key properties summarized above.