made it a lot shorter though the speed is similar due to the fact that yours inserts the value which is slower

Time measurement confirms my hypothesis:

divisors1 4.6103479569997035
divisors3 4.21220756699995
divisors4 4.539421095999842
divisors5 3.7151190190002126

Insert is O(n) (because we have to shift every element after insertion point), so total runtime for list construction will be O(n*n), where n is number of factors. Sort, on the other hand, should be O(n*log(n)), which is asymptotically faster.

guys you have to find all prime numbers that divides this number first this will increase esentially time efficiency

Good one! I'll compare the runtimes with mine.