For a given number N check if it is prime or not. A prime number is a number which is only divisible by 1 and itself.

Example 1:
Input:
N = 5
Output:
1
Explanation:
5 has 2 factors 1 and 5 only.
Example 2:
Input:
N = 25
Output:
0
Explanation:
25 has 3 factors 1, 5, 25
Your Task:
You don't need to read input or print anything. Your task is to complete the function isPrime() which takes an integer N as input parameters and returns an integer, 1 if N is a prime number or 0 otherwise.

Expected Time Complexity: O(sqrt(N))
Expected Space Complexity: O(1)

Constraints:
1 <= N <= 10^{9}

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