Special Number in JAVA

Special Number

Special Number : A number is said to be Special Number if the sum of factorial of its digits is equal to the number itself. 

Example : 145 is a Special Number.

Sum of factorial of digits : 1! + 4!+ 5! = 1 + 24 + 120 = 145 

Input     : 145

Output  : It is a Special Number

Input     : 220

Output  : It is not a Special Number

Algorithm and Program given below :-

Algorithm :- 

• Input a number
• Store it in another variable
• Now using while loop extract last digit of the number
• Than by using for loop store the factorial of the digit
• Than in another variable store the sum of factorial
• initialize sum variable =1 again
• update the value of number by storing it without its last digit
• After the condition satifies completely
• Compare the original number with the sum of factorial of digits
• If both are equal than display "It is a special number"
• Else display "It is not a special number

Program :-

import java.io.*;
import java.util.*;
class Special
{
    public static void main(String args[])
    {
        Scanner in = new Scanner(System.in);
        int n,p,i,num,sum=1,s=0;
        System.out.println("Enter Number ");
        n= in.nextInt(); //Input Number
        p=n; // Storing the input number
        while(n>0)
        {
            num=n%10; // extracting last digit of the number
            for(i=num;i>=1;i--)
            {
                sum=sum*i; //storing factorial of the extracted digit
            }
            s= s+sum; // storing the sum of factorials
            sum=1; //again initializing sum=1
            n=n/10; // updating value of the number by storing it without its last digit.
        }
        if(s==p)// comparing sum of factorial with original number
        {
            System.out.println("It is a Special Number : "+p);
        }
        else
        {
            System.out.println("It is not a Special Number : "+p);
        }
    } // end of main method
} // end of class 

Program Video : Watch now

All the Best :)
Keep Learning :)