Q: What is the sum of all factors of the number 21,120 excluding 21,120?

A: 52,320

Why is 52,320 the sum of all factors of 21,120, excluding 21,120?

The factors of the number 21,120 are: 1, 2, 3, 4, 5, 6, 8, 10, 11, 12, 15, 16, 20, 22, 24, 30, 32, 33, 40, 44, 48, 55, 60, 64, 66, 80, 88, 96, 110, 120, 128, 132, 160, 165, 176, 192, 220, 240, 264, 320, 330, 352, 384, 440, 480, 528, 640, 660, 704, 880, 960, 1056, 1320, 1408, 1760, 1920, 2112, 2640, 3520, 4224, 5280, 7040, 10560, 21120.

If you add them up, you will get the total of 21,172. Now subtract 21,120 to get 52,320