Sixty-four

Sixty-four (64, LXIV) is a natural number following sixty-three and preceding sixty-five. It is a composite number with the divisors being 2, 4, 8, 16 and 32. It is the square of 8. Its factorization is:

Sixty-four is also:

• The atomic number of gadolinium, a lanthanide.
• In some computer programming languages, the size in bits of certain data types.
• In chess, the total number of black and white squares on the board.
• The code for international direct dial calls to New Zealand.
• The designation of US Interstate 64, a freeway from Missouri to Virginia.
• The subject of the Beatles song When I'm Sixty-Four
• The registry of the U.S. Navy's aircraft carrier USS Constellation (CV-64)

This article is about the number 64. For the year AD 64, see 64.