Fait général: 9596 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 9596 is the index of a triangular number containing only 3 different digits.
Culture générale: 9596 is a boring number.
Date historique: April 9th is the day in 1981 that the U.S. Navy nuclear submarine USS George Washington (SSBN-598) accidentally collides with the Nissho Maru, a Japanese cargo ship, sinking it.