A comment here mentioned the absolute number of physicians in the United States, so I did some Googling and found a convenient website showing the number of physicians per 10,000 population in different countries. (The primary source for these data is studies by the World Health Organization, but the WHO website is not quite as user-friendly.) Note that in some countries the level of training and clinical experience to become a physician is much higher than in other countries.

http://kff.org/global-indicator/physicians/