Forty is also the only number in the English language which is spelt in alphabetical order.
f ɔ ɹ t i WORD_BOUNDARY ɪ z WORD_BOUNDARY ɔ l s oʊ WORD_BOUNDARY ð ɪ WORD_BOUNDARY oʊ n l i WORD_BOUNDARY n ʌ m b ə ɹ ɹ WORD_BOUNDARY ɪ n ð ɪ WORD_BOUNDARY ɪ ŋ ɡ l ɪ ʃ WORD_BOUNDARY l æ ŋ ɡ w ɪ d̠ʒ WORD_BOUNDARY w ɪ t̠ʃ WORD_BOUNDARY ɪ z WORD_BOUNDARY s p ɛ l t WORD_BOUNDARY ɪ n WORD_BOUNDARY æ l f ə b ɛ t ɪ k ə l WORD_BOUNDARY ɔ ɹ d ə ɹ WORD_BOUNDARY