7. Wikipedia’s highest listed estimate for the Milky Way’s mass is 4.5*10^12 solar masses, each of which is about 2*10^30 kg, each of which is estimated as the equivalent of about 1.67*10^-27 hydrogen atoms. (4.5*10^12 * 2*10^30)/(1.67*10^-27) =~ 5.4*10^69.
7. Wikipedia’s highest listed estimate for the Milky Way’s mass is 4.5*10^12 solar masses, each of which is about 2*10^30 kg, each of which is estimated as the equivalent of about 1.67*10^-27 hydrogen atoms. (4.5*10^12 * 2*10^30)/(1.67*10^-27) =~ 5.4*10^69.