* Phaser types: There were different types of phasers (handheld, rifles, etc.) and multiple phaser banks on the ship.
* Crew usage: The show frequently depicted multiple crew members using phasers in various situations, suggesting there were a significant number.
* Starfleet regulations: The show implied there were regulations for phaser usage and distribution within Starfleet, which suggests a standardized system.
Therefore, it's impossible to say for certain how many phasers were on the Enterprise. The number likely varied depending on the episode and the specific needs of the mission.