MathDB
Interesting numbers

Source: Kvant Magazine No. 4 2022 M2694

March 8, 2023
Kvantnumber theory

Problem Statement

Call a natural number nn{} interesting if any natural number not exceeding nn{} can be represented as the sum of several (possibly one) pairwise distinct positive divisors of nn{}.
[*]Find the largest three-digit interesting number. [*]Prove that there are arbitrarily large interesting numbers other than the powers of two.
Proposed by N. Agakhanov