How many banks are there in the world that I've never even heard of?

I'm constantly amazed at how many banks there apparently are in the world that I've never heard of - if indeed these are legitimate banks.

I must get two-three dozen requests a week in my junk email box from banks that I have remotely heard of but don't know where the closest one would even be or have never heard of to maintain or otherwise access my account (that I don't have),  I know these are purely phishing expeditions on their part, but geez. Enough.