12-Mar-1995

Unsolved Problem 11:

Are there any odd perfect numbers?

A perfect number is a positive integer that is equal to the sum of all its positive divisors, other than itself.
For example, 28 is perfect because 28=1+2+4+7+14.

Reference:

[Shanks 1985]
Daniel Shanks, Solved and Unsolved Problems in Number Theory. Chelsea Publishing Company. New York: 1985. Page 2.
Odd Perfect Numbers
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