Mammoth Uncensored Word List:
8 words that are 27 letters long beginning with q in the mammoth uncensored word list.

quinquagintaducentilliardth quinquagintaducentillionths quinquagintatrecentilliards quinquagintatrecentillionth quinquaquadragintilliardths quinquaquinquagintilliardth quinquaquinquagintillionths quinquaseptuagintilliardths