Other scholars put forward that the number 666 is obtained through the use of gematria, an early form of Jewish mysticism. Its object is to conceal a name by substituting for it a cipher of equal numerical value to the letters composing it. When the name "Nero Caesar" is spelled with Hebrew letters as נרון קסר (NRWN QSR — Hebrew is written without vowels.) Each letter has a corresponding numerical value. N=50, R=200, W=6 N=50, Q=100, S=60, R=200, resulting in the sum of 666. Some Greek manuscripts of Revelation have a different number. Here the number is not 666, but 616. If Nero is alternatively spelled as NRW instead of NRWN you get 616; NRWN minus N(=50)
James Morgan Pryse also notes that according to this method of figuring, the Greek term ἡ φρην, which signifies the lower mind, has 666 as its numerical equivalent. It is also well known to Qabbalists that Ἰησους, Jesus, has for its numerical value another sacred and secret number--888. Adding the digits of the number 666 and again adding the digits of the sum gives the sacred number--9 the symbol of man in his unregenerate state and also the path of his resurrection.
Other believed the Beast number to be a certain year. Because of this, the year 666 AD was looked on as the date for the advent of the Antichrist. When that date came and went, the year 1666 was then looked on with dread. Nostradamus pointed to the year 1999 as an inverted 666 year.
there have been many attempts to show that a person is the Antichrist by relating his name to the number 666.
One interpretation is simply that 666 represents humankind in general because of the special significance that the number has in the Bible. Six is known as an "imperfect number" because it is one short of seven, the "perfect number" (seven days in the week, seven tongues of flame, seven spiritual gifts...). So three (the number of the Trinity) sixes is seen as extremely imperfect. Therefore, 666 represents imperfect man, while 777 represents God.
A more radical interpretation is that 666 is actually some kind of code based on the letters of someone's name. This sparks great public interest since it seems to provide some way to identify the antichrist. Numerologists like to devise clever ways of assigning numbers to letters so that the letters of a name will add up to this symbolic number. Depending on how you figure it, 666 can be made to add up to just about anyone's name.
For example, scholars who believe the Book of Revelation refers to real people and events argue that the number represents the value of Nero or Neron Caesar (נרון קסר, Nrwn Qsr*) in Hebrew letters, which also have numerical values.
r S q n w r n
666 = 200 + 60 + 100 + 50 + 6 + 200 + 50
Some early texts of the Book of Revelation use 616 instead, which would represent the alternative Hebrew spelling נרו קסר, Nrw Qsr:
r S q w r n
616 = 200 + 60 + 100 + 6 + 200 + 50
*Note: Hebrew נרון קסר, Nrwn Qsr = Greek Νερων Καισαρ, Nerôn Kaisar, though קסר, qSr, should strictly speaking be כסר, kSr.
Probably the best-known scheme has A=100, B=101, and so on. With this code, the name "HITLER" adds up to 666. While these ideas are intriguing, they usually require many odd preconditions (you have to start with 100, you cannot include the first name) and work in a few languages only (in Spanish, for example, "HITLER" adds up to 668.)
In Roman numerals 666 represents all the numbers from 1 to 500 in descending order, namely D (500) + C (100) + L (50) + X (10) + V (5) + I (1), or DCLXVI. Robert Graves suggests in his study of pagan symbolism The White Goddess that this is an acronym for the Latin sentence Domitianus Caesar Legatos Xti Violenter Interfecit, or "The Emperor Domitian violently killed the envoys of Christ".
In an alternate style of greek notation for numerals, 6 + 60 + 600 can be expressed as digamma koppa kappa which when superposed into a monogram, form the graffito form of the labrys very common on roman walls of the time, which is interesting considering what some characterise as misogynist tendencies in Revelations.