Fatto generale: 9181 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 9181 is an uninteresting number.
Trivia: 9181 is an unremarkable number.
Data storica: February 18th is the day in 1745 that the city of Surakarta, Central Java is founded on the banks of Bengawan Solo River, and becomes the capital of the Kingdom of Surakarta.