Fatto generale: 15698 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 15698 is an uninteresting number.
Trivia: 15698 is an unremarkable number.
Data storica: December 23rd is the day in 1972 that the 16 survivors of the Andes flight disaster are rescued after 73 days, having survived by cannibalism.