666 is sometimes referred to as the “Number of the Beast,” which arose from the cryptic reference in the Book of Revelation (13:17–18) (the Textus Receptus manuscripts of the New Testament) that this number is “man’s number” or “the number of a man.” Today, the number is often used and widely recognized as a symbol for the devil (the Antichrist). That said, in China, the number is often considered lucky.
For those betting folks in the audience, 666 is the sum of all the numbers (0 through 36) on a roulette wheel and for you linguists reading this, the fear of 666 or the digits 6-6-6 is known as hexakosioihexekontahexaphobia.