There are 330 million (33 Crore) Devtaa in Hindu mythology. There are 33 Mool Devee Devtaa as mentioned in Ved. They are 12 Aaditya, 8 Vasu, 11 Rudra, Indra and Prajaapati (some say 2 Ashwinee Kumaar). All these are from Hiranyagarbh.

12 Aaditya are - Mitra, Savitra, Aaryaman, Daksh, Bhag, Ansh, Twashtra, Pooshan, Shaktra, Vaivaswat, and Vishnu.

Vishnu literally means "he one who occupies everything". Since He is supposed to take up the task of protection and sustenance, he became the most likable form. In the task of establishing the balance in Dharm, He is supposed to incarnate whenever Dharm is deteriorating. He has incarnated 9 times and he 10th one is yet to take place. Those who worship the Supreme as Shiv, and follow Shaiv Puraan, believe that Shiv has taken 100 incarnations. It is really interesting to see that Shiv Sahastra Naam contains many names of Vishnu and Vishnu Sahastra Naam contains many names of Shiv. Even Shankar who has advised Panchaayatan Poojaa includes Shiv and Vishnu along with Devee, Soorya and Ganapati. Shiv Panchaayatan is where Shiv is in the center and Vihnu Panchaayatan is where Vishnu is in center.

Shivasya Hridayam Vishnu, Vishnushch Hridayam Shivah
Yathaa Shiv Mayam Vishnuh ....