Perfect Numbers

Perfect Numbers are numbers which are equal to the sum of their proper divisors.

For example, the first few perfect numbers are 6, 28, 496, 8128, ... since

6 = 1 + 2 + 3,
28 = 1 + 2 + 4 + 7 + 14,
496 = 1 + 2 + 4 + 8 + 16 + 31 + 62 + 124 + 248
8128 = 1 + 2 + 4 + 8 + 16 + 32 + 64 + 127 + 254 + 508 + 1016 + 2032 + 4064

The first eight perfect numbers are summarized in the following table:

n Number
1 6
2 28
3 496
4 8128
5 33550336
6 8589869056
7 137438691328
8 2305843008139952128

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