Find if given number is prime or not

Question

I am trying to find if 5915587277 is prime or not. This number is actually prime and I am expecting this from my program. When I run this program it says that it is not prime and its divisor is 199.

#include<stdio.h>

int main()
{
    long n = 0;
    long i = 0;
    printf("Enter Number: ");
    scanf("%ld", &n);
    long m = n/2;

    if(n%2 == 0)
    {
        printf("Not Prime");
        return 0;
    }

    for( i = 3; i <= m; i++)
    {
        if(n%i == 0)
        {
            printf("Not Prime: %d\n", i);
            return 0;
        }

    }

    printf("Prime");
    return 0;
}

I am not sure why this code is printing this number as NOT prime when it is.

Answer 1

You are exceeding the max value for a long. See Data type limits.