Q: What is the sum of all factors of the number 2,780 excluding 2,780?
A: 3,100
The factors of the number 2,780 are: 1, 2, 4, 5, 10, 20, 139, 278, 556, 695, 1390, 2780.
If you add them up, you will get the total of 2,783. Now subtract 2,780 to get 3,100