How many Prophets / Religions were there in total? ?

Well, according to Muslims...everyone is a Muslim and every famous person in history was a Muslim. Most were Islamic prophets (even if they never even heard of Islam). Budha, Alexander the Great, Confucious, Jesus, Moses, Dracula, Frankenstein.....

In reality though...Muhommad invented Islam about 1500 years ago by combining what he knew of Judaism and Christianity with the current (at that time) Arab moon-God religion of Al-Ilah. He may or may not have come up with the idea on his own...it may have been inspired by Satan (who knows?). Either way, it worked out well for him (kind of like Warren Jeffs).