An airplane can have varying numbers of engines depending on its size and type. Single-engine planes are common among smaller regional and private aircraft, while commercial airliners usually feature two to four engines. On the other hand, larger military and cargo planes may have as many as six or more engines.
It's worth noting, however, that some aircraft like gliders or ultra-light planes don't have any engines and instead rely on alternate methods such as towing or utilizing wind currents to remain airborne.