The number 666 has long been respected as an object of dark mystery; it is well-known as the Number of the Beast as described the Book of the Revelation :

Here is wisdom. Let him that hath understanding count the number of the beast: for it is the number of a man; and his number is Six hundred threescore and six.
Book of Revelation 13:18. From the King James translation

Today we’re not going to look over the apocalypticism, prophecy, mysticism, nor the numerology properties of 666, we’re going to see that mathematically, 666 is a fascinating number!

• The sum of the first 36 natural numbers is 666 (1 + 2 + 3 + … + 34 + 35 + 36 = 666)

• 666 is the sum of the squares of the first seven prime numbers (22 + 32 + 52 + 72 + 112 + 132 + 172 = 666).

• 666 = 16 - 26 + 36

• It is equal to the sum of its digits plus the cubes of its digits:

• 666 = 6 + 6 + 6 + 6³ + 6³ + 6³.

• 666 is related to (6² + n²) in the following interesting ways:666 = (6 + 6 + 6) · (6² + 1²)
  666 = 6! · (6² + 1²) / (6² + 2²)

• 666 is a Smith number, since 666 = 2·3·3·37

A Smith number is an integer in which the sum of its digits is equal to the sum of the digits of its prime factors.while at the same time
6 + 6 + 6 = 2 + 3 + 3 + 3 + 7.

• A standard function in number theory is phi(n), which is the number of integers smaller than n and relatively prime to n. Remarkably,

phi(666) = 6·6·6.

Now here’s some word game related to the Number of the Beast :

• The Roman numeral representation of the number 666 (DCLXVI) uses once each the Roman numeral symbols with values under 1,000, occurring in descending order of their respective values (D = 500, C = 100, L = 50, X = 10, V = 5, I = 1). What’s the best English chronogram for 666? Here’s one that’s pretty apt: Expect The Devil.

• SIX
  SIX
  SIX
  +BEAST
  ———
  SATAN

• The ancient Greek word for “the Latin speaking man” is LATEINOS
  L = 30 lambda
  A = 1 alpha
  T = 300 tau
  E = 5 epsilon
  I = 10 iota
  N = 50 nu
  O = 70 omicron
  S = 200 sigma
  ————
  666

• Note that 1998 = 666 + 666 + 666. Not only that, but if we set A=3, B=6, C=9, etc., we find, amazingly, thatNINETEEN NINETY EIGHT = 666

• And in ancient Greek the word for “tradition” PARADOSIS P = 80 pi
  A = 1 alpha
  R = 100 rho
  A = 1 alpha
  D = 4 delta
  O = 70 omicron
  S = 200 sigma
  I = 10 iota
  S = 200 sigma
  ——————-
  666

Credits :

The Number of the Beast
666, The Number of the Beast
666 dashboard image was taken from The Number of the Beast
The other two was already at My Pictures folder in my PC, I forgot where was I saved them from