using System;

using System.Xml;

using System.Xml.Linq;

using System.Linq;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        var raw = @"<Report>

    <Incidentreport Company='company1' ID='sample'>

       <status i_number='12345678' status='sucessful' />

    </Incidentreport>

</Report>";

        var doc = new XmlDocument();

        doc.LoadXml(raw);

        var result = doc.SelectSingleNode("/Report/Incidentreport/status/@i_number");

        Console.WriteLine(result.Value);

    }

}