Java Program to Check a number is Magic Number or Not

In mathematics, if the sum of its digits recursively is calculated till a single digit. If the single digit is 1 then the number is called a magic number. It is quite similar to the happy number.

For example, 325 is a magic number because the sum of its digits (3+2+5) is 10, and again sum up the resultant (1+0), we get a single digit (1) as the result. Hence, the number 325 is a magic number.

 Code:

import java.util.Scanner;  

public class CheckMagicNumber 

{  

    public static void main(String args[])  

    {  

        int n, remainder = 1, number, sum = 0;  

        //creating a constructor of the Scanner class  

        Scanner sc = new Scanner(System.in);  

        System.out.print("Enter a number you want to check: ");  

        //reading an integer form the user  

        n = sc.nextInt();  

        //assigning the entered number in the variable num  

        number = n;  

        //outer while loop  

        while (number > 9)    //while(number > 0 || sum > 9)  

        {  

            //inner while loop      

            while (number > 0)  

            {  

            //determines the remainder      

            remainder = number % 10;   

            sum = sum + remainder;  

            //divides the number by 10 and removes the last digit of the number  

            number = number / 10;     

            }  

            number = sum;  

            sum = 0;  

        }  

        if (number == 1)  

        {  

        System.out.println("The given number is a magic number.");  

        }  

        else  

        {  

        System.out.println("The given number is not a magic number.");  

        }  

    }  

}  

Output: