Given a positive integer x, calculate the sum of all of the divisors of the number. Please include the number itself in your final answer. For example, 1, 3, 5 and 15 are all the proper divisors of 15, so sum_divisors(15)=1+3+5+15, which is 24.
Your score will be based on how quickly your script solves the problems in the test suite, rather than the typical Cody size. Good luck!