As I was reading the intro for Dante, I kept coming across references labeled "Aeneid 6" which were obviously referring to Book 6 where Aeneas journeys through the underworld. However as I kept looking at this citation I began to wonder if 6 became associated with the devil's number because Aeneas travels to the underworld in Book 6.
So, I did some research. Wikipedia tells me that it was actually from the Book of Revelation of the New Testament. Furthermore, as most of us already know, the devil's number is actually 666 as mentioned here. Wikipedia also told me that this was mentioned in Chapter 13. Is this why the number 13 is considered unlucky in pop culture?
It's pretty interesting when you start to question some of the origins of popular beliefs. I don't think I've actually stopped to consider the significance of the things we associate with numbers. I'm pretty amazed right now.