##### Short Problem Definition:

Count factors of given number N.

##### Link

##### Complexity:

expected worst-case time complexity is `O(sqrt(N))`

expected worst-case space complexity is `O(1).`

##### Execution:

This example can be found in the lesson document.

##### Solution:

```
def solution(N):
cnt = 0
i = 1
while ( i * i <= N):
if (N % i == 0):
if i * i == N:
cnt += 1
else:
cnt += 2
i += 1
return cnt
```