Revelation written in Hebrew or in Greek ? ?
The passages about the Antichrist, it says, are related to the the reader in Greek and in Hebrew.
"They [ the demonic locusts ] have a king over them, the angel of the abyss, his name in HEBREW is Abaddon and in GREEK he has the name Apollyon." (Rev. 9:11)
There is good reason to believe that the angel of the bottomless pit or the abyss here is the Antichrist. And the fact that we are given heads up that he has a Hebrew name and a Greek name could be related to the calculation of his number.
Not checking on the particulars, I do recall that by combining the transliteration of Hebrew syllables and Greek syllables you do come up with the number 666.
It has little to do with what language Revelation was written in.
" Here is wisdom. Let him who has understanding calculate the number of the beast, for it is the number of a man; and his number is six hundred sixty six. " (Rev. 13:18)
Maybe, the reference to the Greek and Hebrew names of Antichrist are a hint that the "wisdom" needed to calculate the name calls on this consideration.
Without Greek and Hebrew fonts I cannot print all the info I am looking at at the moment. But we have something like this:
Nero Kaiser (Greek syllable transliterated (?) to Hebrew letter)
50 + 200 + 6 + 50 =
306
100 + 60 + 200 =
360
306 + 360 = 666 .