PalPrime Number Java

The PalPrime number is a special positive number which is also known as the Palindromic Prime number. A number is said to be a palindromic prime if the number is a palindrome as well as a prime. So, a number having properties of both the palindrome and prime number is referred to as the PalPrime number or Palindromic Prime number.

A palindrome number is a number that remains the same after reversing each digit of that number.

A prime number is a number that is divisible by only one or itself.

So, a number that remains the same after reversing each digit of the number and that number is divisible by itself, or one is referred to as the PalPrime number.

Let's take some examples of PalPrime numbers.

313 is a PalPrime number because after reversing that number, the number retains its original value, and the number is also divisible by only one or itself.
252 is not a PalPrime number because after reversing the number, the number retains its original value, but it is not only divisible by one or itself.
353 is also a prime number because it follows the properties of palindrome and prime number both.

Steps to check PalPrime number

In order to check whether the number is PalPrime or not, we have to follow the following steps:

Get a number from the user to check whether it is PalPrime or not.
We store that number in a temporary variable so that the original value remains the same.
We use the "for loop" to check whether the number is prime or not.
We also check whether the number is palindrome or not.
If the number is both Prime and Palindrome, print "number is a PalPrime number.".
If not, then print "number is not a PalPrime number.".

Let's implement the code to check whether the number is a PalPrime number or not.

PalPrimeNumber.java

//import required classes and packages
import java.io.*;
import java.util.*;

//create PalPrimeNumber class to check whether the given number is a PalPrime number or not
class PalPrimeNumber
{	
	//main() method start
    public static void main(String args[])
    {
		//create scanner class object to get input from user
        Scanner sc = new Scanner(System.in);
		
		//declare and initialize variables 
        int number, temp, rem, i;
		int count = 0;
		int sum = 0;
		
        System.out.println("Enter number to check");
        //get input from user
		number = sc.nextInt();
        
		//store number in a temporary variable temp
		temp = number;
        
		//use for loop check whether number is prime or not
		for(i = 1; i <= temp; i++)
        {
            if(temp%i == 0)
            {
                count++;	//increment counter when the reminder is 0
            }
        }
		
		//use while loop to check whether the number is palindrome or not
        while(number > 0)
        {
			// get last digit of the number
            rem = number%10;
			
			// store the digit last digit
			sum = sum*10+rem; 
            
			// extract all digit except the last
			number = number/10; 
        }
		
		//check whether the number is palindrome and Prime or not
        if(temp == sum && count == 2)
        {
            System.out.println(temp +" is a PalPrime number");
        }
        else
        {
            System.out.println(temp +" is not a PalPrime number");
        }
    }
}

Output:

FindAllPalPrimeNumbers.java

//import required classes and packages
import java.io.*;
import java.util.*;

//create FindAllPalPrimeNumber class to get all the ORE number in the given range
class FindAllPalPrimeNumber
{	
	//main() method start
    public static void main(String args[])
    {
		int startRange, endRange;
		
		//create scanner class object
		Scanner sc=new Scanner(System.in);
		
		//show custom message
		System.out.println("Enter start value");
		
		//store user entered value into variable startRange
		startRange = sc.nextInt();
		
		//show custom message
		System.out.println("Enter last value");
		
		//store user entered value into variable endRange
		endRange = sc.nextInt();
		
		System.out.println("The PalPrime Numbers between" + startRange + " and " + endRange + "are:");
		for(int i = startRange; i <= endRange; i++){
			if(checkPalPrimeNumber(i))
				System.out.println(i);
		}
        
	}
	
	static boolean checkPalPrimeNumber( int number){
		
		//declare and initialize variables 
        int temp, rem, i;
		int count = 0;
		int sum = 0;
		
		//store number in a temporary variable temp
		temp = number;
        
		//use for loop check whether number is prime or not
		for(i = 1; i <= temp; i++)
        {
            if(temp%i == 0)
            {
                count++;	//increment counter when the reminder is 0
            }
        }
		
		//use while loop to check whether the number is palindrome or not
        while(number > 0)
        {
			// get last digit of the number
            rem = number%10;
			
			// store the digit last digit
			sum = sum*10+rem; 
            
			// extract all digit except the last
			number = number/10; 
        }
		
		//check whether the number is palindrome and Prime or not
        if(temp == sum && count == 2)
			return true;
        else
			return false;
	}
}

Output: