История изменений

https://en.wikipedia.org/wiki/Number_of_the_Beast

In the Greek manuscripts, the Book of Revelation is titled The Apocalypse of John[3] where this number is rendered in Greek numerical form as χξϛ,[4] or sometimes literally as ἑξακόσιοι ἑξήκοντα ἕξ, hexakósioi hexēkonta héx, «six hundred and sixty-six»

Хотя до сих пор непонятно, может быть это 616

Around 2005, a fragment from Papyrus 115, taken from the Oxyrhynchus site, was discovered at the Oxford University's Ashmolean Museum. It gave the beast's number as 616 χιϛʹ. This fragment is the oldest manuscript (about 1,700 years old) of Revelation 13 found as of 2015.[15][16]

UPD: То есть клеймо может быть «χξϛ» или «χιϛʹ». Наверное, допускалось и другими символами, лишь бы цифры совпадали

https://en.wikipedia.org/wiki/Number_of_the_Beast

In the Greek manuscripts, the Book of Revelation is titled The Apocalypse of John[3] where this number is rendered in Greek numerical form as χξϛ,[4] or sometimes literally as ἑξακόσιοι ἑξήκοντα ἕξ, hexakósioi hexēkonta héx, «six hundred and sixty-six»

Хотя до сих пор непонятно, может быть это 616

Around 2005, a fragment from Papyrus 115, taken from the Oxyrhynchus site, was discovered at the Oxford University's Ashmolean Museum. It gave the beast's number as 616 χιϛʹ. This fragment is the oldest manuscript (about 1,700 years old) of Revelation 13 found as of 2015.[15][16]