Arguably, yes it is 616, due to misreading. If we accept 616 as the number of the beast then, ironically for metal bands at least, it spells gig in 1337. But 666 is more commonly accepted.
666 is believe to be the number of the beast because it is the number of man an imperfect number, rather that the number of God 777, which it falls just short of in every way.
It is thought that if 3 sevens (the number of God) represent the son, the father, and the Holy Spirit, the 3 sixes represent Satan, the false prophet (some believe this will be another of the fallen angels possible Lucifer) and the Anti-Christ (the son of Satan and therefore Christ's nemisis)
In early Greek references to Christianity, the number is recognised (in the Greek alphabet) as 666 (six hundred and sixty six) rather than 6 6 6 (three individual 6's) again in some Greek texts it is recognised as 616.
666 is the sum of the squer of the first 7 prime numbers.
Commonly accepted theories on what the number means, mostly revolve around it being code for a persons name, thus allowing us to actaully determine the exact name of the Anti-Christ. However this is disputed because given different calculations, and phonetic, graphematical stuctures and languages, almost any name can be made to relate to 666.
Examples - Some theorists argue that the number is a reference to emperor Nero. Baring in mind Anchient Hebrew is written backwards and doesn't feature vowels, Ceasar/Kaiser Nero would appear thus - rsqnwrn.
Applying Hebrew numerical values to letters, this would come out as 200, 60, 100, 50, 6, 200, 50. The sum of the numbers is 666.
Removing one of the <n>, leaves a difference of 50, however in some Hebrew texts Nero is referred to as rsq wrn. Using the same system as before the numerical values of these letter add to 616.
At one point, Ronald Reagan was considered by some Muslim fundamentalist groups to the "the Beast", as each of his names contained 6 letters (his middle name is Wilson).
This was also perpetuated by among less educated Muslims when Ayatollah Khomeini reffered to Reagan as "the great Satan", infact this was a (perhaps deliberate) mistranslation, as the words for <enemy> and <Satan> are the same in Arabic. Wheather this translation was misinterpreted by the papers to 'cause controversy or by Khomeini for the same reasons, in retalition for Americans campaigns in the middle east during the 80's, is unclear.
Reagan also once lived at house number 666 Bel-Air California.
There is speculation that the number points to Bill Gates. Gates full name, William Henry Gates, adds to 663 when written in Microsofts ASCII format, adding the III of his title (as he is Bill Gates the Third) his anme adds to 666.
Other theories include the idea that the number should be transalted in Roman numerals DCLXVI, leading to one theory that is an abbreviation of "Domitianus "Caesar Legatos Xti Violenter Interfecit" - <The Emperor Domitian violently killed the envoys of Christ>.
On the other hand it is proposed that DCLXVI is an anagram of DIC LVX, an abbreviation of "dicit lux" - <the light speaks>.
The final and perhaps most disconserting theory is that 666 points to the molecule Carbon 12, which contains 6 protons, 6 neutrons and 6 electrons, and is the elements from which all life is formed on the planet (and the know universe) it is poetically the building block of man, as man is mortal he is there for, unlike God, imperfect, again falling just short of God in every way.
Sorry about that just I love the mythology behind fairy stories and Christianity happens to be one of the best ones.