Fatto generale: 5554 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 5554 is a Kaprekar number for cubes.
Trivia: 5554 is an unremarkable number.
Data storica: March 16th is the day in 1940 that First person killed in a German bombing raid on the UK in World War II during a raid on Scapa Flow in the Orkney Islands, James Isbister.