Check given number is prime number or not using c program

Definition of prime number:

A natural number greater than one has not any other divisors except 1 and itself. In other word we can say which has only two divisors 1 and number itself. 

Their divisors are 1 and 5.

Note: 2 is only even prime number.

Logic for prime number in c

We will take a loop and divide number from 2 to number/2. If the number is not divisible by any of the numbers then we will print it as prime number.

Example of prime numbers : 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199 etc.

#include<stdio.h>

int main(){

    int num,i,count=0;

    printf("Enter a number: ");

    scanf("%d",&num);

    for(i=2;i<=num/2;i++){

        if(num%i==0){

         count++;

            break;

        }

    }

   if(count==0 && num!= 1)

        printf("%d is a prime number",num);

   else

      printf("%d is not a prime number",num);

   return 0;

}

Sample output:

Enter a number: 5

5 is a prime number