1. Forty is the only number in English whose letters appear in alphabetical order.
2. Minus 40 degrees, or “40 below,” is the only temperature that is the same in both Fahrenheit and Celsius.
3. When the bubonic plague gripped Europe during the Middle Ages, ships would be isolated in harbor for 40 days before passengers could go ashore. The Italian word for 40 is quaranta—hence quarantine.
4. There are 40 spaces on a standard Monopoly board. Proving that life is a gamble, the game gives players equal odds (one in 40) of going directly to jail or winning the Free Parking lottery.
5. Forty is the maximum number of players a Major League Baseball team can sign to its roster at once.
6. Forget “nine months”; a typical pregnancy actually lasts 40 weeks.
7. It took chemists 40 attempts to develop the magical spray we know as … wait for it … WD-40 (full name: Water Displacement, 40th formula).
8. In literature, 40 is the number of thieves Ali Baba clashes with in Arabian Nights.
9. Also, 40 is the number of winks Dr. William Kitchiner suggests taking for a perfect nap.
10. In religion, 40 seems to be shorthand for “a long time.” Jesus spent 40 days fasting in the wilderness being tempted by the devil; the great flood lasted 40 days and 40 nights; the Jewish people wandered the desert for 40 years.
11. And if you need more evidence that 40 sounds like a lot, please see the standard American workweek: 40 hours.
Sources: todayifoundout.com, npr.org, dicegames.org, mlbdailydish.com, babycenter.com, wd40.com, britannica.com, gutenberg.net, and dol.gov