Fait mathématique: 9031 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Culture générale: 9031 is an uninteresting number.
Date historique: September 21st is the day in 1964 that the North American XB-70 Valkyrie, the world's first Mach 3 bomber, makes its maiden flight from Palmdale, California.