The number 6 is unique in a way that it is the sum of all of its positive divisors (excluding itself), i.e. 1,2 and 3.
Find the next (two digit) number that exhibits such a trait.
Answer
The required answer is the number 28 with 1,7 and 14 as its divisors.
Such numbers are called perfect numbers. A few others include 496 and 8128...
