Quote Originally Posted by Caledonian View Post
...suggesting that it's not merely a designation, but describes an objective aspect of its nature. Possibly there is an inherent arrangement or structure to the multiverse that the numbering system refers to.
Still doesn't explain how Mysterio (or at least his scriptwriter) magically knew the number though.

(I acknowledge it's not hugely important, it's just like a splinter that I can't remove.)