Question: how many aedra are there?
Answer: Eight of the Aedra are worshipped as the Eight Divines, namely Akatosh, Arkay, Dibella, Julianos, Kynareth, Mara, Stendarr, and Zenithar (with the addition of Talos, the human god-hero Tiber Septim, they have become the Nine Divines).