56 is the 6th tetrahedral number.
56 is a friendly number.
In chess Edit
It is also the number of possible bishop moves in 4×4 minichess.
In googology Edit
In Greek-based number-naming systems, 56 is associated with prefix "hexapentaconta-", and with prefix "sexquinquaginti-" in Latin systems.
56 is the last 2 digits of mega.