Hecho matemático: 81966 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Trivia: 81966 is an uninteresting number.
Fecha histórica: May 31st is the day in 1973 that the United States Senate votes to cut off funding for the bombing of Khmer Rouge targets within Cambodia, hastening the end of the Cambodian Civil War.