Write a program to input a number and print whether the number is a special number or not. (A number is said to be a special number if the sum of the factorial of the digits of the number is the same as the original number).

Java Programming Language (Article) (Program)

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Write a program to input a number and print whether the number is a special number or not. (A number is said to be a special number if the sum of the factorial of the digits of the number is the same as the original number).

Example: 145 is a special number because 1! + 4! + 5! = 1 + 24 + 120 = 145 (where ! denotes factorial of the number, and the factorial value of a number is the product of all integers from 1 to that number, e.g., 5! = 1 × 2 × 3 × 4 × 5 = 120).

Program:

import java.io.*;

class Special {

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int n, r, f, i;
        int sum = 0;
        int originalNumber;

        System.out.println("Enter a number:");
        n = Integer.parseInt(br.readLine());
        originalNumber = n;

        while (n > 0) {
            r = n % 10; // Extract the last digit
            f = 1; // Initialize factorial
            for (i = 1; i <= r; i++) {
                f *= i; // Calculate factorial
            }
            sum += f; // Add factorial to the sum
            n /= 10; // Remove the last digit
        }

        if (sum == originalNumber) {
            System.out.println("Special number.");
        } else {
            System.out.println("Not a Special number.");
        }
    }
}

Output:

Explanation:

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