Six hundred forty
640 is an even number.
640 is a Harshad number, which means it is divisible by the sum of its digits (6 + 4 + 0 = 10, and 640 is divisible by 10).
In binary, 640 is represented as 1010000000.
In hex, 640 is represented as 280.
Prime factorization of 640: 27 * 5.
Factors of 640 are: 1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 64, 80, 128, 160, 320, 640.