Hecho general: 81997 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Hecho matemático: 81997 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Trivia: 81997 is a boring number.
Fecha histórica: July 1st is the day in 1942 that the Australian Federal Government becomes the sole collector of Income Tax in Australia as the State Income Tax is abolished.