what is prime number in c code example

Example 1: prime number c program

int isPrime(int n) {
  for (int i = 2; i < n; i++) if (n % i == 0) return 0; 
  return 1;
}

Example 2: prime check in c

int isPrime(long long number) {

	if (number == 0 || number == 1 || (number % 2 == 0 && number > 2)) {
		return 0;
	}

	else {
		for (long long i=3; i <= (long long)sqrt(number)+1; i++) {
			if (number % i == 0) {
				return 0;
			}
		}
		return 1;
	}
}