👉 A perfect number is a positive integer that is equal to the sum of its proper divisors (excluding itself). In other words, it has no positive divisors other than 1 and itself. For example: - 6 = 1 + 2 + 3 - 28 = 1 + 2 + 4 + 7 + 14 Perfect numbers are fundamental in number theory as they provide insight into the distribution of prime factors among integers, and have applications