Q: What is the sum of all factors of the number 6,390 excluding 6,390?
A: 10,458
The factors of the number 6,390 are: 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, 71, 90, 142, 213, 355, 426, 639, 710, 1065, 1278, 2130, 3195, 6390.
If you add them up, you will get the total of 6,400. Now subtract 6,390 to get 10,458