Untitled

#include <stdio.h>
#include <math.h>

/* Check whether a number given is prime or not.*/

main()
{
        int A, num;

        #define max 2147483647
        #define min -2147483648

        printf("Enter an integer between and including -2147483648 and 2147483647: ");
        scanf("%d", &num);

        if(num < min || num > max){
                printf("This is not a valid input. Aborting.\n");
                return 0;
        }

        for(A=2; A<num/2; A++){
                if(num % A == 0){
                        printf("%d is not a prime number. It is completely divisible by %d.\n",num,A);
                        return 0;
                }
        }
        printf("%d is a prime number.\n",num);
        return 0;
}