how to Convert integer value to time in c#

Question

I have i time in Integer = 59400 , how can I convert it in C# to Timeformat
= 22:03:00.0000000


My C# Code is below

 private void LoadOvertimetotal()

    {

        SqlCommand cmd = new SqlCommand();

        cmd.Connection = con;

        con.Open();

        string str = "SELECT total_sec  = SUM(( DATEPART(hh, Overtime_HHMM) * 3600 ) +( DATEPART(mi, Overtime_HHMM) * 60 ) + DATEPART(ss, Overtime_HHMM)) FROM   Accounts_DailyAttendance where UserID='" + gvStaffDetails.SelectedRow.Cells[2].Text.ToString().Trim() + "' and datename(month,processdate) ='" + Session["paymonth"] + "' and datepart(yyyy,processdate)='" + Session["payyear"] + "' and Overtime_HHMM<>'00:00:00.0000000'";

        string strtotminutes = "SELECT totalovertime =  CONVERT(TIME, DATEADD(s, total_sec, 0))FROM Accounts_DailyAttendance";

        cmd = new SqlCommand(str, con);

        cmd = new SqlCommand(strtotminutes, con);

        SqlDataReader reader = cmd.ExecuteReader();

        reader.Read();

        lbltotalovertime.Text = reader["totalovertime"].ToString();

        reader.Close();

        con.Close();

    }


Thanks