AFAIK (newspaper this morning, I'm no bible buff) revelation 13 verse 18 talks about the number of the beast. It says that the number of the beast is the number of a human namely 666.

The intriging part about this is that Hebrew uses numbers as letters, so 666 could also be a name, the name of the antichrist who apparently has a human form. (I don't know for sure, but I thought that the Hebrew written language doesn't use vowels, so the name could be longer than just 3 identical letters).