Carbon at an atomic level has 6 protons, 6 electrons and 6 neutrons.
Our physical body is made up of 18% Carbon (by mass), the second most abundant element in our bodies, after oxygen.
So then why is '666' referred to as the mark of the beast?
It was so, because the ones who created this term have little respect for humanity, they do not see us as equals. This can be observed in many areas of life. I don't need to go into this so deeply, have a look around. Look at how they live.
The Occupy movement around the Earth did not happen for no reason. A monumental moment in 2011 when representatives of the 99% around the planet stood up against an alleged 1% who appear to have the majority of the world's money and power.
Perhaps it was another way to invoke fear within the masses by way of a depraved in-joke?
666 is a number of creation, it is a number within your very atomic structure. In that respect, 666 has the opposite meaning to that which has been popularly conveyed.
Make friends with 666, give it a hug, you are extremely far from being a beast! (And if you're not, have a shave and a wash as soon as possible) :p