Most applicants apply broadly, often somewhere in the range of 15 to 30 schools. The right number depends on your stats and, more importantly, on how balanced your list is. The goal is a healthy mix: some reach schools, a solid core of targets where your GPA and MCAT sit inside each school's published ranges, and a few likelier options.
Use the MSAR to check every school's numbers, mission, and in-state bias, and include DO schools if you are open to them. Applying to a long list of top-20 programs you are not competitive for mostly drains your money and time. A realistic, well-researched list beats a pile of famous names every cycle.