Program to Check Whether a Number is Prime or Not

We check the divisibility of the given number N with all the numbers starting from 2 to (N/2).
If it is completely divisible by any number i.e. remainder is zero after division, then the number is not a prime number.
If it is not completely divisible by a number between 2 and (N/2), then the number is a prime number.

// C Program to check for prime number using Naive Approach
#include <stdio.h>

// Function to check prime number
void checkPrime(int N)
{
	// initially, flag is set to true or 1
	int flag = 1;

	// loop to iterate through 2 to N/2
	for (int i = 2; i <= N / 2; i++) {

		// if N is perfectly divisible by i
		// flag is set to 0 i.e false
		if (N % i == 0) {
			flag = 0;
			break;
		}
	}

	if (flag) {
		printf("The number %d is a Prime Number\n", N);
	}
	else {
		printf("The number %d is not a Prime Number\n", N);
	}

	return;
}

// driver code
int main()
{
	int N = 546;

	checkPrime(N);

	return 0;
}