static void Main(string[] args)
{
string e = "E";
double d = 0.000012013;
string s = d.ToString(e);
Console.WriteLine(s);
string s3 = string.Format("{0}E({1})",
s.Substring(0, 5),
s.Substring(
s.LastIndexOf(e) + 1, 4).Replace("0", "")
);
Console.WriteLine(s3);
Console.ReadLine();
}