Fait mathématique: 1665 is the number of triangles of any size contained in the triangle of side 18 on a triangular grid.
Culture générale: 1665 is an unremarkable number.
Date historique: July 22nd is the day in 2002 that Israel kills Salah Shahade, the Commander-in-Chief of Hamas's military arm, the Izz ad-Din al-Qassam Brigades.