General fact: 8990 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Mathematical fact: 8990 is an uninteresting number.
Trivia: 8990 is a boring number.
Historical date: August 11th is the day in 3114 BC that the Mesoamerican Long Count calendar, used by several pre-Columbian Mesoamerican civilizations, notably the Mayans, begins.