This number includes:
* 85 novels in the 87th Precinct series, written under the name "Ed McBain."
* 3 standalone novels written under his real name, Evan Hunter.
* 2 novels written under the pseudonym Richard Marsten.
* 3 books written under the pseudonym Evan Hunter, which included 2 non-fiction books and 1 novel.
So, while the number of books written by Ed McBain under his own name is 57, the total number of books written by Evan Hunter, including those under different pseudonyms, is much higher.