54 is the number of cards in a deck of cards including jokers.
In googology Edit
In Greek-based number-naming systems, 54 is associated with prefix "tetrapentaconta-", and with prefix "quattuorquinquaginti-" in Latin systems.
The Okojo numbers are heavily based on the number 54.
In TV broadcasting Edit
In the Americas, the Band I starts at 54 MHz.