About 20 or so. All are based on a few root ideas with the site necessary modifications. Easy to remember, and yes the are written down on paper. No loooking at it you would not suspect they are passwords.
Now I will not tell you format, base, or decision tree
Not counted them, probably about 15 or so; but a different pass-word for every site. Different user-name too, where that's needed.
I run a secondary e-post account on Outlook, and every so often Microsoft asks me to verify my 'phone number as a security test. That's fine except that I had moved house since establishing it, and MS still has the 'phone number for that address.... but gives me no method for up-dating it three years after my move!