Custom number format: #,,, (4)
using System; using System.Globalization; public class MainClass{ public static void Main(){ double value = 1234567890; Console.WriteLine(value.ToString("#,,", CultureInfo.InvariantCulture)); // Displays 1235 Console.WriteLine(value.ToString("#,,,", CultureInfo.InvariantCulture)); // Displays 1 Console.WriteLine(value.ToString("#,##0,,", CultureInfo.InvariantCulture)); // Displays 1,235 } }