Fait général: 63724 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 63724 is an uninteresting number.
Culture générale: 63724 is an unremarkable number.
Date historique: June 20th is the day in 1895 that the Kiel Canal, crossing the base of the Jutland peninsula and the busiest artificial waterway in the world, is officially opened.