Fait général: 28013 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 28013 is a boring number.
Culture générale: 28013 is an unremarkable number.
Date historique: September 10th is the day in 2003 that Anna Lindh, the foreign minister of Sweden, is fatally stabbed while shopping, and dies the following day.