Q: What is the sum of all factors of the number 1,815 excluding 1,815?
A: 1,377
The factors of the number 1,815 are: 1, 3, 5, 11, 15, 33, 55, 121, 165, 363, 605, 1815.
If you add them up, you will get the total of 1,816. Now subtract 1,815 to get 1,377