Hi Friend,

Try this:

import java.math.*;
import java.util.*;
class ProductOfDigits{
        public static void main(String[] args){
        Scanner input=new Scanner(System.in);
        System.out.print("Enter Number: ");
        BigInteger bi=input.nextBigInteger();
        String strSum = bi.toString();
        BigInteger num=new BigInteger("1");
        for(int i = 0;i < strSum.length(); i++){
        char ch=strSum.charAt(i);
        num=num.multiply(new BigInteger(Character.toString(ch)));
        }
        System.out.println(num);
        }
}

Thanks