quintillion

American  

[kwin-til-yuhn] / kwɪnˈtɪl jən /

noun

• quintillions,
  plural
• quintillion
  plural

1. a cardinal number represented in the U.S. by 1 followed by 18 zeros, and in Great Britain by 1 followed by 30 zeros.

---

adjective

1. amounting to one quintillion in number.

quintillion British  

/ kwɪnˈtɪljən /

noun

1. US and Canadian word: nonillion.  (in Britain, France, and Germany) the number represented as one followed by 30 zeros (10 ³⁰ )

2. Former Brit word: trillion.  (in the US and Canada) the number represented as one followed by 18 zeros (10 ¹⁸ )

---

Other Word Forms

Derived Forms

• quintillionth
  noun
• quintillionth
  adjective

Inflected Forms

Nouns

• quintillion
  plural
• quintillions
  plural

Etymology

Origin of quintillion

1665–75; < Latin quīnt ( us ) fifth + -illion (as in million )

Example Sentences

See Examples For:

quintillion quintillions

These rare particles can exceed 100 exa-electron volts, or 100 quintillion electron volts.

From Science Daily ● Jun. 9, 2026

Popular opinion and media coverage say that picking a perfect bracket is effectively impossible, as the odds are allegedly 9.2 quintillion to 1.

From MarketWatch ● Mar. 18, 2026

Europe recently unveiled a rival, Jupiter, housed in western Germany, also able to perform at least one quintillion calculations per second, which is equivalent to about a million smartphones.

From Barron's ● Nov. 26, 2025

There are more than 10 quintillion insects on Earth, 200 million for every human.

From Science Magazine ● Mar. 29, 2024

This liquid mass totals 2,250,000,000 cubic miles and could form a sphere with a diameter of sixty leagues, whose weight would be three quintillion metric tons.

From Twenty Thousand Leagues Under the Sea by F. P. Walter

Interplanetary space contains just a few dozen particles in each cubic centimeter — in comparison, the air we breathe has tens of quintillions of molecules per cubic centimeter.

From Salon ● Jun. 3, 2025

"The right answer emerges every 10 minutes, and the rest of the data, quintillions of them, are computations that serve no further purpose and are therefore immediately discarded," de Vries says.

From Science Daily ● Nov. 29, 2023

The molecules in a single drop can number in the quintillions, and their small mass makes the oils volatile, quick to evaporate at room temperature.

From New York Times ● May 10, 2021

To stave off malignancies, a human body must safely negotiate quintillions of chromosomal splits in a lifetime, versus mere trillions for a mouse.

From Slate ● Nov. 18, 2011

And a positronic brain, which with ten pounds of matter and a few quintillions of positrons runs the whole show.

From "I, Robot" by Isaac Asimov