Fatto generale: 4098 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 4098 is the number of subsets of the 26^{th} roots of unity that add to 1.
Trivia: 4098 is an unremarkable number.
Data storica: March 21st is the day in 1919 that the Hungarian Soviet Republic is established becoming the first Communist government to be formed in Europe after the October Revolution in Russia.