I've actually never had to command it with reduced capacity, but probably something around thirty or forty. We'd need officers on the bridge and a few down at engineering too, not to mention other minor systems that may seem unimportant but are just as vital to keep her running smoothly.

She's a large ship. Some in my world of similar size or even bigger have been designed to run with a crew number as small as one, but none of those are currently commissioned. And yeah, she's the average size of Federation exploratory ships.