Hecho matemático: 15684 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Trivia: 15684 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fecha histórica: December 9th is the day in 1979 that the eradication of the smallpox virus is certified, making smallpox the first and to date only human disease driven to extinction.