When the addition of the divisors of a number equals the number itself it is said to be perfect.
Divisors of 6 ->1, 2, 3 and 1+2+3=6 ,Divisors of 28->1, 2, 4, 7, 14 and 1+2+4+7+14=28
1st number=6, 2nd number=28.
There are many numbers like these
Find the difference between the 7th and the 6th perfect number.