40 (number). 40 (forty) is the number that is after thirty-nine and before forty-one. The prime factors of forty are 2 and 5. (2 * 2 * 2 * 5 = 40) Forty is also the only number in the English language which is spelt in alphabetical order. 40 or forty commonly refers to: 40 (number), the natural number following 39 and preceding 41 one of the years 40 BC, AD 40, 1940, 2040 40 or forty may also refer to: Escucha LOS40 y entérate de todas las últimas noticias musicales y todo sobre los programas Anda Ya, Del 40 al 1 y LOS40 Global Show. LOS40 - Todos los éxitos Provided to YouTube by Universal Music Group 40 (Remastered 2008) · U2 War ℗ 2008 Island Records, a division of Universal Music Operations Limited Released on: 2008-01-01 Vocalist, Composer. 40 – 살구잼과 크래커 (Apricot Jam & the Cracker) | Official Live Clip 5.8K views • 7 months ago 3:51 The number 40 is found in many traditions without any universal explanation for its use. In Jewish, Christian, Islamic, and other Middle Eastern traditions it is taken to represent a large, approximate number, similar to umpteen. We combed through popular culture, literature and history for the most fascinating facts about 40, so you could decide for yourself. Read on, and get ready to have a new favorite number.