using System;

using System.Linq;

public class Program

{   

    private static Random random = new Random();

    public static void Main()

    {

      DateTimeOffset now = DateTimeOffset.UtcNow;

        string random = RandomString(7);

        long unixTimeMilliseconds = now.ToUnixTimeMilliseconds() * Convert.ToInt64(random);

        Console.WriteLine(unixTimeMilliseconds);

    }

     public static string RandomString(int length)

        {

            const string chars = "1234567890";

            return new string(Enumerable.Repeat(chars, length)

              .Select(s => s[random.Next(s.Length)]).ToArray());

        }

}

​

​