Fatto matematico: 8991 is the smallest number so that it and its successor are both the product of a prime and the 5^{th} power of a prime.
Trivia: 8991 is an uninteresting number.
Data storica: August 12th is the day in 1624 that the president of Louis XIII of France's royal council is arrested, leaving Cardinal Richelieu in the role of the King's principal minister.