Revelation 13:17-18 Contemporary English Version Anglicised (CEVUK00)

17. they all had to have this mark, or else they could not buy or sell anything. This mark stood for the name of the beast and for the number of its name.

18. You need wisdom to understand the number of the beast! But if you are clever enough, you can work this out. Its number is six hundred and sixty-six, and it stands for a person.

Revelation 13