my solution (in my test case { 12657445, 89745368, 1235437 }) is about 1000x faster than most popular solution on codewars.
Sum by Factors https://www.codewars.com/kata/54d496788776e49e6b00052f
Given an array of positive or negative integers
I= [i1,..,in]
you have to produce a sorted array P of the form
[ [p, sum of all ij of I for which p is a prime factor (p positive) of ij] ...]