Hecho general: 4375 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Hecho matemático: 4375 is a perfect totient number.
Trivia: 4375 is an uninteresting number.
Fecha histórica: December 23rd is the day in 1968 that the 82 sailors from the USS Pueblo are released after eleven months of internment in North Korea.