PalindromePrime.java

package Misc;

import java.util.Scanner;

public class PalindromePrime {

  public static void main(String[] args) { // Main funtion
    Scanner in = new Scanner(System.in);
    System.out.println("Enter the quantity of First Palindromic Primes you want");
    int n = in.nextInt(); // Input of how many first palindromic prime we want
    functioning(n); // calling function - functioning
    in.close();
  }

  public static boolean prime(int num) { // checking if number is prime or not
    for (int divisor = 3; divisor <= Math.sqrt(num); divisor += 2) {
      if (num % divisor == 0) {
        return false; //  false if not prime
      }
    }
    return true; // True if prime
  }

  public static int reverse(int n) { //  Returns  the reverse of the number
    int reverse = 0;
    while (n != 0) {
      reverse *= 10;
      reverse += n % 10;
      n /= 10;
    }
    return reverse;
  }

  public static void functioning(int y) {
    if (y == 0) return;
    System.out.print(2 + "\n"); // print the first Palindromic Prime
    int count = 1;
    int num = 3;
    while (count < y) {
      if (num == reverse(num) && prime(num)) { // number is prime and it's reverse is same
        count++; // counts check when to terminate while loop
        System.out.print(num + "\n"); // print the Palindromic Prime
      }
      num += 2; // inrease iterator value by two
    }
  }
}