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 a boring number.
Data storica: August 12th is the day in 30 BC that Cleopatra VII Philopator, the last ruler of the Egyptian Ptolemaic dynasty, commits suicide, allegedly by means of an asp bite.