106,456,367,669 (Source : How Many People Ever Lived On Earth)
This number was estimated in 2002 since then we must have added another 720M people to the earth.
Current living population : 6,800,300,000 (Wikipedia)
And when it comes to density of population, India is one of the most densely populated. About 400 people per a square Kilometer. Compare it with USA’s rate of just 34 and China’s 141 to put that number in context.
(Image Source : Wikipedia )