How many Olympian gods were there in greek mythology?

There are 12 main gods, Zeus, Poisideon, Hades, Hera, Aphrodite, Athena, Ares, Dionysus, Hephasus, Hermes, Apollo, Artemis. There are also many minor gods, for a small example, Hecate, godess of magic, Nemisis, godess of revenge and Iris, godess of rainbows. So there are a lot.