Fatto generale: 28231 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 28231 is an unremarkable number.
Trivia: 28231 is an uninteresting number.
Data storica: April 16th is the day in 1947 that Bernard Baruch coins the term "Cold War" to describe the relationship between the United States and the Soviet Union.