6 and 13 – Rebellion
Yes man is marked by the number 6. He is marked by time, 60 seconds, 60 minutes, and man was commanded to work by the sweat of his brow 6 days a week.
Also in 6, in the line or genealogy of Cain (the first child born, and the first murderer) there are only 6 generations recorded, and then God stopped documenting this evil line. Mankind is marked and stamped with the number 6.