How many books are there in the divergent series?

There are 39 chapters in Divergent. It's approximately 500 pages long.

Divergent is a young adult novel about a girl named Beatrice living in dystopian Chicago where society has been divided into factions dedicated to various virtues. Every person must pick one group, and therefore virtue, to which they will dedicate the rest of their lives. Beatrice has trouble choosing and makes choices, goes through initiations, and makes and breaks friendships. This book is the first in Veronica Roth's four book series; it was made into a film in 2014 starring Shailene Woodley and Theo James.