the prime numbers code example

Example 1: 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 ...

Example 2: prime number

#include<bits/stdc++.h>
using namespace std;
bool Is_Prime(long long x){
	if(x%2==0)return false;
	for(int i=3;i*i<=x;i+=2)
		if(x%i==0)return false;
	return true;
}
int main(){
	long long x;
	cin>>x;
	if(Is_Prime(x))cout<<"Is Prime";
	else cout<<"Is not Prime";
}

Example 3: prime numbers

A number only divisible by 1 and itself

Example 4: prime number

public class Prime {
    public static void main(String[] args) {

        int num = 29;
        boolean flag = false;
        for(int i = 2; i <= num/2; ++i){
            if(num % i == 0){
                flag = true;
                break;
            }
        }

        if (!flag)
            System.out.println(num + " is a prime number.");
        else
            System.out.println(num + " is not a prime number.");
}}