The sum is 144 if 60 is included, 84 if not.
28
The even factors of 60 are: 2, 4, 6, 10, 12, 20, 30, 60.
60
60
1 + 3 + 5 + 15 = 24
2, 4, 6, 10, 12, 20, 30, 60 add up to 144.
All of the [positive] whole-number factors of 24 are: 1, 2, 3, 4, 6, 8, 12, and 24. Their sum is 60.
Every one of them has an even number of factors.
36 and 24
1 and 2.
All of them.