Fatto matematico: 1345 is the number of permutations of 8 elements that have 5^{th} power equal to the identity permutation.
Trivia: 1345 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Data storica: September 6th is the day in 1847 that Henry David Thoreau leaves Walden Pond and moves in with Ralph Waldo Emerson and his family in Concord, Massachusetts.