Fatto generale: 375 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 375 is a truncated tetrahedral number.
Trivia: 375 is a boring number.
Data storica: January 9th is the day in 475 that Byzantine Emperor Zeno is forced to flee his capital at Constantinople, and his general, Basiliscus gains control of the empire.