During his 40 years in Europe, he wrote 19 books and declined several prestigious academic positions.
taken from:
http://www.answers.com/topic/george-santayana
Burmese Days (1934) , A Clergyman's Daughter (1935) , Keep the Aspidistra Flying (1936) , Coming Up for Air (1939) , Animal Farm (1945) and Nineteen Eighty-Four (1949)
at least the integer 23
1,200
48 books in total
Dr. Seuss, whose full name was Theodor Seuss Geisel, published over 60 books. He was born in 1904 and died in 1991.