General fact: 4233 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Mathematical fact: 4233 is a heptagonal pyramidal number.
Trivia: 4233 is a boring number.
Historical date: August 3rd is the day in 1959 that Portugal's state police force PIDE fires upon striking workers in Bissau, Portuguese Guinea, killing over 50 people.