Hexakosioihexacontahexaphobia

Holy shit! You’d dislocate your jaw trying to pronounce that and still not be sure if you got it right. It’s fear of the number 666 and goes back to the Book of Revelation in the Bible where 666 is the number of the beast. Interestingly when Ronald and Nancy Reagan left the White House in 1989 and moved to Los Angeles, they insisted on changing the address of their house from 666 St Cloud Road to 668 St Cloud Road.