Use ToString() to format integers : Integer format : Data Type C# Examples

    
using  System;  
  
class  MainClass  {  
    public  static  void  Main()  {  
        int  x  =  21;  

        string  str  =  x.ToString("X");  
        Console.WriteLine(str);  
  
        str  =  x.ToString("D12");  
        Console.WriteLine(str);  
  
    }  
}