I am doing factorial problem and getting this error message:

Runtime Error 
Hangup (SIGHUP)
Traceback (most recent call last):
  File "Solution.py", line 24, in <module>
    for i in ans:
TypeError: 'int' object is not iterable

this is my code

class Solution:

def factorial(self, N):
    
    if N == 1:
        return 1
        
    else: 
        return N * self.factorial(N - 1)