I know I'm getting crazy.
I tried to print all 4032 factors of 15! (in full decimal representation) into a textView, and the app got frozen for about 10 seconds.
I tried to print all 14688 factors of 18! (in full decimal representation) into a textView, and the app got frozen for over a minute.
I tried to print all ??? factors of 20! (in full decimal representation) into a textView, and the app got frozen forever.
So is there a size limit of textView? Did I hit the limit so the app got frozen?
EDIT: I timed the factorization and factor-building processes. They are both lightning fast - under 1 second. So I assume the problem is textView?