40 (number)

40 (number)

40 (forty) is the natural number following 39 and preceding 41.

Despite being related to the word "four" (4), 40 is spelled "forty", and not "fourty". The reason is that etymologically (also in accents without the horse–hoarse merger), the words have different vowels, "forty" containing a contraction in the same way that "fifty" contains a contraction of "five". This makes it the only number which, when spelled out in full, has its letters in alphabetical order.