There is a nested loop, though. Within the first loop, a function call is made to getDivisors() which enters a second loop. It's more readable by being placed into its own function, though.

I always thought this kind of problem would require a nested loop. But your approach gave me a new perspective. What a nice representation of functional programming.

Very beautiful statute.

I don't think there's a more efficient way than this.

Maybe marginally better if you skip prime numbers.

nice solution ! Is there any chance not to make iteration through all elements of array ?