Fatto generale: 99559 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 99559 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Trivia: 99559 is an uninteresting number.
Data storica: July 31st is the day in 1938 that Bulgaria signs a non-aggression pact with Greece and other states of Balkan Antanti (Turkey, Romania, Yugoslavia).