Fait mathématique: 1546 is the number of 5×5 binary matrices with at most one 1 in each row and column.
Culture générale: 1546 is an unremarkable number.
Date historique: March 25th is the day in 1807 that the Swansea and Mumbles Railway, then known as the Oystermouth Railway, becomes the first passenger carrying railway in the world.