Question: how many square feet of land on earth?
Answer: The total land surface area of Earth is about 57,308,738 square miles, of which about 33% is desert and about 24% is mountainous. Subtracting this uninhabitable 57% (32,665,981 mi2) from the total land area leaves 24,642,757 square miles or 15.77 billion acres of habitable land.