Fatto generale: 984 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 984 is an uninteresting number.
Trivia: 984 is a boring number.
Data storica: September 10th is the day in 1919 that Austria and the Allies sign the Treaty of Saint-Germain recognizing the independence of Poland, Hungary, Czechoslovakia and Yugoslavia.