General fact: 4098 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Mathematical fact: 4098 is the number of subsets of the 26^{th} roots of unity that add to 1.
Trivia: 4098 is an uninteresting number.
Historical date: March 21st is the day in 1943 that Wehrmacht officer Rudolf Christoph Freiherr von Gersdorff plots to assassinate Adolf Hitler by using a suicide bomb, but the plan falls through.