Fatto generale: 98511 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 98511 is a boring number.
Trivia: 98511 is an unremarkable number.
Data storica: September 17th is the day in 1948 that the Nizam of Hyderabad surrenders his sovereignty over the Hyderabad State and joins the Indian Union.