To reproduce: 
            DataTable dt = new DataTable();
            dt.Columns.Add("Id", typeof(int));
            dt.Columns.Add("Name", typeof(string));
            dt.Columns.Add("NumberAsShort", typeof(ushort));
            for (int i = 0; i < 100; i++)
            {
                dt.Rows.Add(i, "Row" + i, i );
            }
            this.radGridView1.DataSource = dt;

Workaround: use the CellFormatting event https://docs.telerik.com/devtools/winforms/gridview/cells/formatting-cells