using System;

public class Program

{

    public static void Main()

    {

        var d = 1234567.8790220911;

        //d = Math.Truncate(d * 100) / 100;

        //Console.WriteLine(d);

        //for (var i = 0; i < 10; ++i) {

            //Console.WriteLine(d.ToString("N2") + "\t" + d.ToString("0.00#"));

            var returnStr = d.ToString("N2");

            //var returnStr = String.Format("{0:c3}",d);

             //If there is a decimal point present

            if (returnStr.Contains("."))

            {

                //Remove all trailing zeros

                returnStr = returnStr.TrimEnd('0');

​

                //If all we are left with is a decimal point

                if (returnStr.EndsWith(".")) //then remove it

                    returnStr = returnStr.TrimEnd('.');

            }

            Console.WriteLine(returnStr.Replace(",",""));

            //d /= 10.0;

        //}

    }

}