IMO 2016 Shortlist C2

Find all positive integers n for which all positive divisors of n can be put into the cells of a rectangular table under...

IMO 2016 Shortlist C2

Category: Combinatorics

Problem

Find all positive integers n for which all positive divisors of n can be put into the cells of a rectangular table under the following constraints: • each cell contains a distinct divisor; • the sums of all rows are equal; and • the sums of all columns are equal.