According to wikipedia: 44 people in the US and one big company that owns 30:

https://en.wikipedia.org/wiki/Mikoyan-Gurevich_MiG-21#Civili...

Numbers from 2012 tho... But probably won't be too different now.

More than 11.000 were made, wow.

Well, there's one guy in Palo Alto who had instructor permit on it even, and was looking for partner in its ownership (quite common solution for more expensive planes in civilian hands).