What is the smallest perfect number greater than 6?

Answer 1

Euclid found the four first even perfect numbers by using the formula (2^n -1)(2^n -1).

For n = 2 he found 6.

For n = 3 he found 28. Let's compute it.

(2^n -1)(2^n -1)

(2 ^3-1)(2^3 - 1) = (4)(7) = 28. Let's check if this is true.

Factors of 28 are 1, 2, 4, 7, 14, and 28.

1 + 2 + 4 + 7 + 14 = 28.

For n = 5 Euclid found 496, and for n = 7 he found 8128.