← Complete problem index

PROJECT EULER · #0342

The Totient of a Square Is a Cube

Statement only · SolvedOriginal problem ↗

Consider the number 50.
502=2500=22×54, so ϕ(2500)=2×4×53=8×53=23×53. 1
So 2500 is a square and ϕ(2500) is a cube.

Find the sum of all numbers n, 1<n<1010 such that ϕ(n2) is a cube.

1 ϕ denotes Euler's totient function.

Write-up coming later

The complete problem is available here. An approach, code, and answer will be added later.