Python Program for Find sum of even factors of a number

In this article, we will learn about the solution to the problem statement given below −

Problem statement

Given a number input n, the task is to Find the sum of even factors of a number.

Here we first need to eliminate all the odd factors.

If the number input is odd it has no even factors therefor return zero directly , otherwise, we will follow the approach in the code below

Below is the implementation −

Example

 Live Demo

import math
# Returns sum of all even factors of n.
def sumofFactors(n) :
   # If n is odd
   if (n % 2 != 0) :
      return 0
   #all prime factors
   res = 1
   for i in range(2, (int)(math.sqrt(n)) + 1) :
      count = 0
      curr_sum = 1
      curr_term = 1
      while (n % i == 0) :
         count= count + 1
         n = n // i
         # here we remove the 2^0 that is 1. All other factors
         if (i == 2 and count == 1) :
            curr_sum = 0
         curr_term = curr_term * i
         curr_sum = curr_sum + curr_term
      res = res * curr_sum
   # if n is prime number
   if (n >= 2) :
      res = res * (1 + n)
   return res
# main
n = 20
print(sumofFactors(n))

Output

36

All the variables are declared in the global frame as shown in the figure given below −

Conclusion

In this article, we learned about the approach to Find the sum of even factors of a number