Perfect number
From Simple English Wikipedia, the free encyclopedia
A number is called a perfect number if by adding all the positive divisors of the number (except itself), the result is the original number.
Six is the first perfect number. Its divisors (other than the number itself: 6) are 1, 2, and 3 and 1 + 2 + 3 equals 6. Other perfect numbers include 28, 496 and 8128.