Fatto generale: 1569 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 1569 is the number of labeled mappings from 5 points to themselves with exactly 1 cycles.
Trivia: 1569 is an unremarkable number.
Data storica: April 17th is the day in 1984 that Police Constable Yvonne Fletcher is killed by gunfire from the Libyan People's Bureau in London during a small demonstration outside the embassy.