Quadrillion

In Canadian and U.S. usage, one quadrillion equals 1,000,000,000,000,000, or 10¹⁵.

In European usage, one quadrillion equals 10²⁴. One European quadrillion equals one U.S. septillion?.

While Britain and Australia traditionally employed the European usage, they have recently largely switched to the U.S. version.

See also: number names