Twenty one thousand nine hundred eighty
21980 is an even number.
21980 is a Harshad number, which means it is divisible by the sum of its digits (2 + 1 + 9 + 8 + 0 = 20, and 21980 is divisible by 20).
In binary, 21980 is represented as 101010111011100.
In hex, 21980 is represented as 55dc.
Prime factorization of 21980: 22 * 5 * 7 * 157.
Factors of 21980 are: 1, 2, 4, 5, 7, 10, 14, 20, 28, 35, 70, 140, 157, 314, 628, 785, 1099, 1570, 2198, 3140, 4396, 5495, 10990, 21980.