666 is the mark of the beast (satan). According to
the holy bible:
'[...] Rev 13:16: And he causeth all, both small and great, rich and poor, free and bond, to receive a mark in their right hand, or in their foreheads.
Rev 13:17: And that no man might buy or sell, save he that had the mark, or the name of the beast, or the number of his name.
Rev 13:18: 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. [..]'
