DCLXVI = 666 Just to point out that the no. 666 is actually DCLXVI in roman numerals, and that D,C,L,X,V and I, in turn, are the first six symbols in the roman numerical system in reverse order (i.e. I, V, X, L, C and D backwards). It's like us writing 9,8,7,6,5,4,3,2,1,0, and then someone coming along to add them all up to get 45! John (apparently) wrote the book of Revelation in Greek, but I think he quite likely used the Roman system for numbers (…historians feel free to correct me…), as, although the Greeks did have their own numeral system for a while, they were under Roman rule at John's time (Arabic/Indian numerals weren't in use in that region until centuries later). Perhaps its not the number itself that's significant, but the fact that it can be represented by numbers. And what can be represented by numbers? Wealth of course, in the form of money! 'No one might be able to buy or sell unless they had the mark of the beast (...non-monetary wealth...) or the number corresponding to his name (...monetary wealth...).' (Rev 13.17) I'm only guessing that the author was using the term to represent wealth, but I do think it's quite likely that he actually wrote DCLXVI Opinions anyone? P.S. Apparently χξς is used in some (Greek) versions, but I presume that these are not based on the original Greek. P.S.S. I'm not a religionist; merely an intrigued observer.