Java Programs - Solved 2008 ICSE Computer Science Paper

import java.util.Scanner;
class Menu{
    public static void main(String args[]){
        Scanner in = new Scanner(System.in);
        System.out.println("1. Palindrome number");
        System.out.println("2. Perfect number");
        System.out.print("Enter your choice: ");
        int choice = Integer.parseInt(in.nextLine());
        switch(choice){
            case 1:
            System.out.print("Enter the number: ");
            int n = Integer.parseInt(in.nextLine());
            int rev = 0;
            for(int i = n; i != 0; i /= 10)
                rev = rev * 10 + i % 10;
            if(n == rev)
                System.out.println("Palindrome number!");
            else
                System.out.println("Not a Palindrome number.");
            break;
            case 2:
            int sum = 0;
            System.out.print("Enter the number: ");
            n = Integer.parseInt(in.nextLine());
            for(int i = 1; i <= n / 2; i++){
                if(n % i == 0)
                    sum += i;
            }
            if(n == sum)
                System.out.println("Perfect number!");
            else
                System.out.println("Not a Perfect number.");
            break;
            default:
            System.out.println("Invalid choice!");
        }
    }
}