quadrillion

n 1: (in Britain and Germany) the number that is represented as a

one followed by 24 zeros; "in England they call a

septillion a quadrillion"

2: (in the United States and France) the number that is

represented as a one followed by 15 zeros

quintillion

10^30 in Europe (this is called a {nonillion} in the United

States and Canada).

10^18 in the United States and Canada (this is called a

trillion in Europe).

[Collins dictionary].