Q: What is the sum of all factors of the number 20,640 excluding 20,640?

A: 45,888

Why is 45,888 the sum of all factors of 20,640, excluding 20,640?

The factors of the number 20,640 are: 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 32, 40, 43, 48, 60, 80, 86, 96, 120, 129, 160, 172, 215, 240, 258, 344, 430, 480, 516, 645, 688, 860, 1032, 1290, 1376, 1720, 2064, 2580, 3440, 4128, 5160, 6880, 10320, 20640.

If you add them up, you will get the total of 20,685. Now subtract 20,640 to get 45,888