Some &&GOOOFFFIIIKKK__SLIYMYFUCKINGWRISTS__X kids write it EVERYWHERE to appear cool when really thay appear stupid and amazingly silly as they probably go to church with their mum every Sunday
Me: Yea man.
Friend: Did he just get eaten by a doberman?
Me: Yea man. Lets go get munch.
"...And that number is 666."
Widely implied that it was 666 because it was an imperfect number to represent the impurities of man and their evildoings and sinful ways.
Read the book of revelations, at the end of the New Testament; it tells all about that, the seven seals, the apocalypse, Armageddon, Megiddo, etc...