I got my kicks on Route 666
As well all know, 666 is the number of the 'Antichrist'. But, most of us are a bit unclear about what that means, so we'll look at the more popular conception, which is that 666 is the mark of Satan. You know, Mephistopheles, the Devil, the Lord of the Flies, Lucifer, Old Nick (not to be confused with Jolly old St. Nick, although some parents assembling toys on Christmas Eve would be forgiven for confusing the two), and so on and so forth. We have a lot of names for this familiar dude. We have lots of thoughts about him, too.
We who are raised in Christian, Jewish or Islamic faiths are taught to hate him, yet we must admit that we have a kind of fascination, too. Mick and Keith even expressed 'sympathy' for him. But, I don't think he needs our sympathy other than for the fact that we seem to expect him to work overtime so often do we call for his services. But, that is where the metaphor in the song comes in. We blame Satan for all the terrible things we do. I think we're missing the point. We were given free will to make our choices. Satan, as a sort of amalgam of oily car-salesman, on-line Viagra huckster, and politician (any politician, anywhere, any time in history) merely shows us the options we have if we want to sin. And, a lot of sins are pretty darn enticing, just ask Faust or Dorian Gray.
I think we have to consider something else, too. Satan is in the untenable position of knowing he can never win. God is still the boss -- has to be because Satan is merely a lapsed angel, so therefore was created by God, and blasted out of Paradise for being too damn ambitious -- sort of like a lot of mid-management types. So, Satan was left being boss of just one sector. Of course, he does the best he can with his sector.
One thing he does is invite a lot of mighty interesting folk to be there. I mean, would you rather spend your eternal time with Errol Flynn or Mother Teresa? Oh, not to impugn Mother Teresa, but I bet old Errol has a lot of interesting stories to pass the time. He might even share some of his babes, too, since probably a lot of them are down there with him, too.
I have no real answer for this 666 matter, other than to think it's complete nonsense. On the other hand, I am happy my street address is 658 rather than eight numbers farther along in the numerical scale. It's just a matter of being on the safe side.