Efficient Way to Reverse Numbers in C#

So you would like to reverse the numbers using C#. You can treat the number as a string and directly reverse the number but here is another way to reverse it.  and this on the basis of mathematical formula. The program is given below.

using System;
using System.Collections;

namespace MyApp
{
    class Program
    {
        static void Main(string[] args)
        {
            int iNumber = 450;
            int rev = 0, iLength = iNumber.ToString().Length;
            for (int i = 0; i <iLength; i++)
            {
                rev *= 10;
                rev += (iNumber % 10);
                iNumber /= 10;
            }
            Console.Write(rev.ToString());
            Console.ReadLine();
        }    
    }
}