The Number of the Beast is described in the Book of Revelation 13:18. The original Greek reads:
“ ωδέ η σοφία εστίν; ο έχων νουν ψηφισάτω τον αριθμόν του θηρίου; αριθμός γαρ ανθρώπου εστί; και ο αριθμός αυτού χξς'. ”

The King James translates:
“ Here is wisdom. Let him that hath understanding count the number of the beast: for it is the number of a man; and his number is Six hundred threescore and six. ”

In May 2005, it was reported that scholars at Oxford University using advanced imaging techniques had been able to read previously illegible portions of the earliest known record of the Book of Revelation, from the Oxyrhynchus site, Papyrus 115 or P115, dating to the mid to late third century. The fragment gives the Number of the Beast as 616 (chi, iota, stigma), rather than the majority text 666 (chi, xi, stigma). The other early witness Codex Ephraemi Rescriptus (C) has it written in full: hexakosiai deka hex(lit. six hundred sixteen).

Significantly, P115 aligns with Codex Alexandrinus (A) and Codex Ephraemi Rescriptus (C) which are generally regarded as providing the best testimony to Revelation. Thus, P115 has superior testimony to that of P47 which aligns with Codex Sinaiticus and together form the second-best witness to the Book of Revelation. This has led some scholars to conclude that 616 is the original number of the beast

The 11th century minuscule manuscript Codex 2344 identifies the Number of the Beast as 665 (χξε').