5

This number is a prime.

Single Curio View: (Seek other curios for this number)

Are there any integers n for which σ(σ(n)) = 5n, where σ(n) denotes the sum of all positive divisors of n? [Nie]

Submitted: 2024-03-01 14:53:11; Last Modified: 2024-03-01 16:04:21.