For a misogynistic arsehole like him, I suspect the answer to "how many is too many?" is "no such thing, I can sleep with as many as I like" for him, and "ideally there should have never been anyone but me" for you.
In reality of course, the answer is "as many as you like and have fully mutually consensual (& hopefully enjoyable) sex with".
Any man who asks for your "number" is showing a misogynist red flag - it's none of his business who you were with before him. And if he doesn't accept a polite deflection of the question, even more so.
He was willing to have unprotected sex, so he clearly wasn't more concerned about his sexual health than he was about the pleasure of not wearing a condom.
I'm sorry you're feeling upset, but he's really someone you should be glad to be rid of.
Zero judgment, but for your own safety and peace, please be firm in insisting future partners must use condoms in future - and before you agree to not use them, both of you should have a full, clear, set of STI checks, to which you show each other the text message results to prove you've both done them (anyone could say anything without proof, and people of course do lie). And having clear STI screens is both good for your health and also eliminates any residual excuses for asking about previous partners.