Fatto generale: 28973 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 28973 is an unremarkable number.
Trivia: 28973 is an uninteresting number.
Data storica: April 28th is the day in 1945 that Benito Mussolini and his mistress Clara Petacci are executed by a firing squad consisting of members of the Italian resistance movement.