using System;

using System.Collections.Generic;

using System.Linq;

using System.Xml.Linq;

using System.Globalization;

​

public class Program

{

    public static void Main()

    {

        var result = "2020-01-16T14:29:17.9743131Z0";

        Console.WriteLine(result);          

        var format = "yyyy-MM-dd'T'HH:mm:ss.fffffff";

        Console.WriteLine(DateTime.ParseExact(result, format, CultureInfo.InvariantCulture).ToString());

    }

}