A Perfect Number is a positive whole number
which is the sum of all its proper factors. For example, 28 = 1 + 2 + 4 + 7 +
14.
Show that, for any whole number n, n
is Perfect if and only if the sum of all the reciprocals of its positive
divisors (including itself) is 2.
For example: 1/1 + 1/2 + 1/4 + 1/7 + 1/14 + 1/28 = 2