Friend Number (C# .Net)

        Using System; 
{
      Class Program
      {
          Static void main(String[]args)
        {
          int number Sum=a,n;
          Console.Write("Enter the Number");
          number=int.Parse(Console.ReadLine());
          n=number;
          for (int i=1 ; i<number, i++)
          {
          if(number%i==0)
          {
            Sum=Sum+1;
          }
      }
      if(Sum==n)
      {
        Console.WriteLine("Entered number is friend number");
      }
      else
      {
        Console.WriteLine("Not a friend number");
        Console.ReadKey();
      }
    }
  }
}