What is the relation between Ethereum and the number 18?

I am not a numerologist or a conspiracy theorist at all and I know it may sound silly. Just asking if Vitalik said something about that number, because seems like it’s an important number for him.

• You can divide an ETH in up to 18 decimals
• The annual cap used to be 18 million ETH
• 18 angles in their logo (if you look at it in 2D)
• Initial fund was 18 million USD