A perfect number is a number equal to the sum of all of its proper divisors. Proper divisors are all the divisors of a number with the exception of the number itself. The number 6 is the smallest perfect number; the sum of its divisors-1,2, and 3-equals 6. The next 3 perfect numbers are 28, 496, and 8,126. No odd perfect numbers are known. The highest established perfect number is: (2859,433 -1) X 2859,433.