Java Program to check the accepted number is Armstrong / Palindrome / Perfect number

The following code is to accept any number and check whether it's an Armstrong / Palindrome / Perfect number, depending on the user's choice.
Code:-

import java.util.*;
public class Number{
    Scanner scan=new Scanner(System.in);
    int num,choice=0,i,r,s=0,n;
    public void input()throws IOException{
        try{
            System.out.println("Enter any number: ");
            num=scan.nextInt();
            System.out.println("1 to check "+num+" is Armstrong.\n2 to check "+num+" is Palindrome.\n3 to check "+num+" is Perfect.\nEnter Your Choice: ");
            choice=scan.nextInt();
        }
        catch(Exception e){
            System.out.println("Error: "+e);
            System.exit(0);
        }
    }

    public void compute(){
        System.out.println("Your choice: "+choice);
        System.out.println("Processing.");
        System.out.println("Processing of "+num+" for ");
        if(choice==1)
            System.out.print("Armstrong has completed.\n");
        else if(choice==2)
            System.out.print("Palindrome has completed.\n");
        else
            System.out.print("Perfect has completed.\n");
        switch(choice){
            case 1:
            armstrong(num); break;
            case 2:
            palindrome(num); break;
            case 3:
            perfect(num); break;
            default:
            System.out.println("Your Choice: "+choice+" is invalid.");
        }
    }

    public void armstrong(int num){
        int d;
        n=num;
        while(num>0){
            d=num%10;
            s=s+(d*d*d);
            num/=10;
            if(num==0){
                System.out.println("Before: "+n);
                System.out.println("After: "+s);
                break;
            }
        }
        if(s==n)
            System.out.println("Armstrong.");
        else
            System.out.println("No.");
    }

    public void palindrome(int num){
        n=num;
        while(num>0){
            r=num%10;
            s=s*10+r;
            num/=10;
            if(num==0){
                System.out.println("Before: "+n);
                System.out.println("After: "+s);
                break;
            }
        }
        if(s==n)
            System.out.println("Palindrome.");
        else
            System.out.println("No.");
    }

    public void perfect(int num){
        int tmp=num,sum=0;
        for(i=1;i<num;i++){
            if(num%i==0){
                sum+=i;
                System.out.println("Factor of "+num+" is: "+i);
            }
        }
        System.out.println("Sum of the factors of "+num+" is: "+sum);
        if(sum==num)
            System.out.println("Number "+tmp+" is Perfect.");
        else
            System.out.println("Number "+tmp+" is not Perfect.");
    }

    public static void main(String[] args)throws IOException{
        Number obj=new Number();
        obj.input();
        obj.compute();
    }
}

Output:-
Enter any number:
153
1 to check 153 is Armstrong.
2 to check 153 is Palindrome.
3 to check 153 is Perfect.
Enter Your Choice:
1
Your choice: 1
Processing.
Processing of 153 for
Armstrong has completed.
Before: 153
After: 153
Armstrong.