Hecho matemático: 1921 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Trivia: 1921 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fecha histórica: April 4th is the day in 1913 that the Greek aviator Emmanouil Argyropoulos becomes the first pilot victim of the Hellenic Air Force when his plane crashes.