Fatto matematico: 9191 is not the sum of a square, a cube, a 4^{th} power, and a 5^{th} power.
Trivia: 9191 is an unremarkable number.
Data storica: February 28th is the day in 1993 that Bureau of Alcohol, Tobacco and Firearms agents raid the Branch Davidian church in Waco, Texas with a warrant to arrest the group's leader David Koresh.