Six-hundred-sixty-six or six-six-six or six-one-six Regarding the passage of Revelation 13:18, which is likely the most proper way to present the Beast's number?


600+60+6 (six hundred and sixty six)
6-6-6 (six six six)
600+10+6 (six hundred and sixteen)
6-1-6 (six one six)
The Greek spells out each word:


  ἑξακόσιοι (six hundred) ἑξήκοντα (sixty) ἕξ (six).


At the time the NT was written, place holders were unknown. It was simply not possible to write ἕξ ἕξ ἕξ (or to use the single letters for six which would be three stigmas) and it be understood as six hundred sixty-six. To write out 666 using the letter equivalents would be chi xi stigma (χξϛ). Chi being used for six hundred, xi representing sixty, and stigma being 6 (stigma was used in antiquity only as a numeral). If you did write out ἕξ ἕξ ἕξ or ϛϛϛ, the reader would understand it as "18" because you add up the letters to make the total.

The translator's notes for Revelation 13:18 from the NET Bible concludes that 666 is to be preferred over 616:


  A few mss (Ì115 C, along with a few mss known to Irenaeus {and two minuscule mss, 5 and 11, no longer extant}), read 616 here, and several other witnesses have other variations. Irenaeus’ mention of mss that have 616 is balanced by his rejection of such witnesses in this case. As intriguing as the reading 616 is (since the conversion of Nero Caesar’s name in Latin by way of gematria would come out to 616), it must remain suspect because such a reading seems motivated in that it conforms more neatly to Nero’s gematria.