Quintillion

A quintillion is equal to 1,000,000,000,000,000,000.

Scale

 * It would take 210,000 years for Niagara Falls to have a quintillion gallons of water.
 * The Earth contains 326 quintillion gallons of water.
 * The distance between the Milky Way and Andromeda Galaxy is ~11.73 quintillion miles.
 * A single drop of water contains 1.7 quintillion water molecules.