Fatto generale: 8538 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 8538 is the sum of its proper divisors that contain the digit 4.
Trivia: 8538 is a boring number.
Data storica: May 17th is the day in 1943 that the United States Army contracts with the University of Pennsylvania's Moore School to develop the ENIAC.