It is a tough question. Short answer, there are 85 billion, 500 million currently active website hostnames. A lot of websites run on the same hostname.
In perspective, there are over 100 websites per person on the planet. And trust me, the majority of those are not in use nor have any relevancy to real life. They are just sitting there.
I think there are about 6,000,000,000,000,0005 trees in the entire world. But i am not poisitive
There are 25.21 billion pages on the web. As of March 2011.
There are 8.7 Million animals in the world
billions
85
There is no way to tell because like the universe the internet is ever expanding.
2000 to 4000 in the whole entire world
There are currently about 48 websites in the world, I think. Maybe a little more.
215,675,903
18
there are 1500 in the world
There is only one in the entire world.