Q: What is the sum of all factors of the number 7,800 excluding 7,800?

A: 18,240

Why is 18,240 the sum of all factors of 7,800, excluding 7,800?

The factors of the number 7,800 are: 1, 2, 3, 4, 5, 6, 8, 10, 12, 13, 15, 20, 24, 25, 26, 30, 39, 40, 50, 52, 60, 65, 75, 78, 100, 104, 120, 130, 150, 156, 195, 200, 260, 300, 312, 325, 390, 520, 600, 650, 780, 975, 1300, 1560, 1950, 2600, 3900, 7800.

If you add them up, you will get the total of 7,818. Now subtract 7,800 to get 18,240