666 (number)
Template:About Template:Redirect Template:Infobox number 666 (six hundred [and] sixty-six or triple six) is the natural number following 665 and preceding 667.
In Christianity, 666 is referred to in most manuscripts of chapter 13 of the Book of Revelation of the New Testament as the "number of the beast" or "number of (a) man".<ref>Template:Bibleverse</ref><ref name = "Beale, 718">Beale, Gregory K. (1999). The Book of Revelation: A Commentary on the Greek Text. Grand Rapids, Michigan: Wm. B. Eerdmans Publishing. p. 718. Template:ISBN. Retrieved 9 July 2012.</ref><ref>Template:Cite web</ref>
In mathematics
666 is the sum of the first thirty-six natural numbers, which makes it a triangular number:<ref name="triang">Template:Cite OEIS</ref>
- <math>\sum_{i=1}^{36} i = 1 + 2 + 3 + \cdots + 34 + 35 + 36 = 666</math>.
In fact, 666 is the largest triangular number that is also a repdigit.<ref>Template:Cite journal</ref>
Since 36 is a triangular number too, 666 is a doubly triangular number. Also, 666 is the sum of squares of two consecutive Triangular numbers.
T(15+21) = 152 + 212,
which can be re-written as:
The difference of 21² and 15² is:
Which can be expressed:
216 = (T3) × (T3)² or (TT2) × (TT2)².
666 is a congruent number, as it is possible to make a right triangle with rationally numbered side lengths whose area is 666.<ref>Template:Cite web</ref>
The number of integers which are relatively prime to 666 is 216, <math>\phi (666) = 216</math>;<ref>Template:Cite OEIS</ref> and for an angle measured in degrees, <math>\sin {(666^{\circ})} = \cos{(216^{\circ})} = -\tfrac {\varphi}{2}</math> (where here <math>\varphi</math> is the golden ratio).<ref name="Wells">Template:Cite book</ref><ref>Template:Cite journal</ref>Template:Efn
666 is also the sum of the squares of the first seven primes Template:Nowrap,<ref name="Wells" /><ref>Template:Cite OEIS</ref> while the number of twin primes less than Template:Nowrap is 666.<ref>Template:Cite web
- Template:Nowrap, and the 666th pair of twin primes is (47147, 47149).</ref>
A prime reciprocal magic square based on <math>\tfrac {1}{149}</math> in decimal has a magic constant of 666. The twelfth pair of twin primes is (149, 151),<ref>Template:Cite OEIS</ref> with 151 the thirty-sixth prime number.Template:Efn
666 is a Smith number and Harshad number in base ten.<ref>Template:Cite OEIS</ref><ref>Template:Cite OEIS</ref> The 27th indexed unique prime in decimal features a "666" in the middle of its sequence of digits.<ref>Template:Cite OEIS</ref>Template:Efn
The Roman numeral for 666, DCLXVI, has exactly one occurrence of all symbols whose value is less than 1000 in decreasing order (D = 500, C = 100, L = 50, X = 10, V = 5, I = 1).<ref name="Wells" />
In Christian religion
Number of the beast
Template:Main In the Textus Receptus manuscripts of the New Testament, the Book of Revelation (Template:Bibleverse-nb) cryptically asserts 666 to be "the man's number" or "the number of a man" (depending on how the text is translated) associated with the Beast, an antagonistic creature that appears briefly about two-thirds into the apocalyptic vision. Some manuscriptsTemplate:Which of the original Koine Greek use the symbols χξϛ chi xi stigma (or χξϝ with a digamma), while other manuscripts spell out the number in words.<ref name="gateway-stephanus">Template:Cite web</ref>
In modern popular culture, 666 has become one of the most widely recognized symbols for the Antichrist or, alternatively Satanism. Earnest references to the number occur both among apocalypticist Christian 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 numerical 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.<ref>Novum Testamentum Graece, Nestle and Aland, 1991, footnote to verse 13:18 of Revelation, page 659: "Template:Lang" as found in C [C=Codex Ephraemi Rescriptus]; for English see Metzger's Textual Commentary on the Greek New Testament, note on verse 13:18 of Revelation, page 750: "the numeral 616 was also read ..."</ref><ref>Template:Cite web</ref>
Other occurrences
- In the Bible, 666 is the number of talents of gold Solomon collected each year (see Template:Bibleverse and Template:Bibleverse).
- In the Bible, 666 is the number of Adonikam's descendants who return to Jerusalem and Judah from the Babylonian exile (see Template:Bibleverse).
- Using gematria, Neron Caesar transliterated from Greek into Hebrew short-form spelling, נרון קסר, produces the number 666. The Latin spelling of "Nero Caesar" transliterated into Ktiv haser Hebrew, נרו קסר, produces the number 616. Thus, in the Bible, 666 may have been a coded reference to Nero, who was the Roman emperor from 55 to 68 AD.<ref name="numberphile">Template:Cite web</ref>
In other fields
- The Number of the Beast, the 1982 album by English heavy metal band Iron Maiden, references 666 in its title and the album's title song.
- 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 (0 through 36).<ref name="numberphile"/> This is a corollary of the fact that the number is a Triangular number, as mentioned earlier.
- 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.<ref>Template:Cite news</ref>
- Was the original name of the Macintosh SevenDust computer virus that was discovered in 1998.Template:Citation needed It is also the name of an extension that SevenDust can add to an uninfected Macintosh.<ref>Template:Cite web</ref>
- The number is a frequent visual element of Aryan Brotherhood tattoos.<ref name="Brook-2011">Template:Cite book</ref>
- Aleister Crowley adopted the title "the Beast 666".<ref>Template:Cite web</ref> 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 Chinese numerology, the number is considered to be lucky and is often displayed in shop windows and neon signs.<ref name="China666">Template:Cite book</ref><ref>Template:Cite web</ref> In China, 666 can mean "everything goes smoothly" (the number six has the same pronunciation as the character 溜, which means "smooth".<ref>Template:Cite web</ref>
- Is commonly used by ISPs to blackhole traffic using BGP communities.<ref>Template:IETF RFC</ref>
- 666 Fifth Avenue in New York City, which was bought for $1.8 billion in 2007, was the most expensive real estate deal in New York's history.<ref>Template:Cite web</ref>