In the Textus Receptus manuscripts of the New Testament, the Book of Revelation cryptically asserts 666 to be "man's number" or "the number of a man" associated with the Beast, an antagonistic creature that appears briefly about two-thirds into the apocalyptic vision. Some manuscripts of the original Greek use the symbols χξϛ chixistigma, while other manuscripts spell out the number in words. In modern popular culture, 666 has become one of the most widely recognized symbols for the Antichrist or, alternatively, the devil. The number 666 is purportedly used to invoke Satan. Earnest references to the number occur both among apocalypticistChristian groups and in explicitly anti-Christian subcultures. References in contemporary Western art or literature are, more likely than not, intentional references to the Beast symbolism. Such popular references are therefore too numerous to list. It is common to see the symbolic role of the integer 666 transferred to the digit sequence 6-6-6. Some people take the Satanic associations of 666 so seriously that they actively avoid things related to 666 or the digits 6-6-6. This is known as hexakosioihexekontahexaphobia. The Number of the Beast is cited as 616 in some early biblical manuscripts, the earliest known instance being in Papyrus 115.
Other occurrences
In the Bible, 666 is the number of of gold Solomon collected each year.
Using gematria, Neron Caesar transliterated from Greek into Hebrew produces the number 666. The Latin spelling of "Nero Caesar" transliterated into Hebrew produces the number 616. Thus, in the Bible, 666 may have been a coded reference to Nero, the Roman Emperor from 55 to 68 AD.
In other fields
Is the magic sum, or sum of the magic constants of a six by six magic square, any row or column of which adds up to 111.
Is the sum of all the numbers on a roulette wheel.
Was a winning lottery number in the 1980 Pennsylvania Lottery scandal, in which equipment was tampered to favor a 4 or 6 as each of the three individual random digits.
Was the original name of the Macintosh SevenDust computer virus that was discovered in 1998.
Aleister Crowley adopted the title "the Great Beast 666". As such, 666 is also associated with him, his work, and his religious philosophy of Thelema.
Molar mass of the high-temperature superconductor YBa2Cu3O7.
In China the number is considered to be lucky and is often displayed in shop windows and neon signs. In China, 666 can mean "everything goes smoothly" (the number six has the same pronunciation as the character 溜, which means "smooth".
