Fatto generale: 28708 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 28708 is an uninteresting number.
Trivia: 28708 is an unremarkable number.
Data storica: August 6th is the day in 2008 that a military junta led by Mohamed Ould Abdel Aziz stages a coup d'état in Mauritania, overthrowing president Sidi Ould Cheikh Abdallahi.