How much money are in the world? And how much money can Bitcoin be worth? in comparation to that.
there is no limit of quantity of money banknotes. because people are publishing money to use. they produce it according to demand so you can say money in the world is so so much
we can not finish it by spending 
Yes .Most of us don't know the exact money in this World.But the question was most interesting one.I hink no one will know the answer for this.Since the money in rotation,even the government of certain country can't predict the money in their country.Then we calculate the money in this world.It's seems to be unpredictable.