Fatto generale: 23509 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 23509 is an uninteresting number.
Trivia: 23509 is an unremarkable number.
Data storica: May 12th is the day in 1935 that Bill Wilson and Dr. Bob Smith (founders of Alcoholics Anonymous) meet for the first time in Akron, Ohio, at the home of Henrietta Siberling.