If you removed all of the empty space in the atoms that make up our bodies, you could fit the entire human race inside a single sugar cube.
Water molecules (H2O) are so tiny that a standard cup of water (the size you use for cooking) contains around 8,360,000,000,000,000,000,000,000 of them. If you split that single cup of water between all of the people on Earth, each person would still receive approximately 1,000,000,000,000,000 water molecules
The number googol (1 with a hundred zeros after it) is so big that there is not a googol of anything in the entire universe. Even if you counted every single atom in the universe, you would still be 21 zeroes short of a googol.
Finally, one for the hygiene-conscious. The average healthy adult human contains 30 trillion human cells and 39 trillion bacteria.