Fait général: 21242 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 21242 is an unremarkable number.
Culture générale: 21242 is an uninteresting number.
Date historique: February 26th is the day in 1935 that Robert Watson-Watt carries out a demonstration near Daventry which leads directly to the development of RADAR in the United Kingdom.