The only Greek mythology characters that die are the heros (example: Hercules, Oddyseus, Perseus, Theseus, Achilles, etc...). None of the Gods/Goddesses or Titans die because they are immortal.
There were many goddesses in greek mythology(im not sure that there is a specific number) but to name a few: Athena Hera Artemis Demeter Aphrodite Selene Eos Persephone Hecate Nemesis Hestia