whoops!
Density is wrong.
Volume of space with 50 ly radius is 4.4334805104537358990831872843718e+53 cubic meters.
Density of stars is 2.9999004097660592829390322825833e-52 stars per cubic meter.
Volume of torus representing the Sun's orbit around the galaxy is 1.2535370821327484902395251498925e+57 cubic meters.
Population of star systems with terrestrial planets like our own is 376,049.
Like I said, whoops! Draw your own conclusions.