16 digits Unique numbers

Generate 16 Digit Random Number:
5 digit Random using System.Random Class

5 digit number by using TimeSpan

6 numbers by System Time (HH:MM:SS)

System.Random fiveRandom = new Random();
TimeSpan tsFive = new TimeSpan();
tsFive = System.DateTime.Now.Subtract(Convert.ToDateTime(“01/01/1900”));
Console.WriteLine(fiveRandom.Next(10000, 99999) + tsFive.Days.ToString() + System.DateTime.Now.Hour.ToString(“00”) + System.DateTime.Now.Minute.ToString(“00”) + System.DateTime.Now.Second.ToString(“00”));