fastest way to check if a number is prime + c++ + stl code example

Example 1: check prime in c++

#include <bits/stdc++.h>
#include <math.h>
using namespace std;

#define ll long long

bool checkPrime(int number){
	for(int i=2; i<=sqrt(number); i++){
		if(number%i==0){
			return false;
		}
	}
	return true;
}

Example 2: check prime in c++

#include <bits/stdc++.h>
using namespace std;

#define ll long long
bool isPrime(ll number){
	  for(ll i = 2; i <= number / 2; i++){
	  
  
      	if(number % i == 0)
      {
          return false;
          break;
      }
 	}
 	
 	return true;
}