Fatto generale: 354 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 354 is the sum of the first four 4^{th} powers.
Trivia: 354 is a boring number.
Data storica: December 19th is the day in 1963 that Zanzibar gains independence from the United Kingdom as a constitutional monarchy, under Sultan Jamshid bin Abdullah.