Quintillion — Definition, Formula & Examples
A quintillion is the number 1 followed by 18 zeros, or 1,000,000,000,000,000,000. It is one of the large number names in the naming system used in the United States.
In the short scale (used in the U.S. and most English-speaking countries), a quintillion denotes , equal to one million trillions or one billion billions.
Key Formula
Where:
- = Ten raised to the eighteenth power, meaning 1 multiplied by 10 a total of 18 times
How It Works
Each named large number is 1,000 times the previous one: million, billion, trillion, quadrillion, quintillion. A million is , a billion is , a trillion is , a quadrillion is , and a quintillion is . You can think of a quintillion as multiplying a billion by itself: .
Worked Example
Problem: How many thousands are in one quintillion?
Write each number as a power of 10: One quintillion is and one thousand is .
Divide: Divide the quintillion by one thousand by subtracting exponents.
Answer: There are (one quadrillion) thousands in one quintillion.
Why It Matters
Scientists use quintillions to describe very large quantities. For example, roughly 1.5 quintillion grains of sand exist on Earth's beaches, and computer scientists measure data storage in exabytes, where 1 exabyte equals 1 quintillion bytes.
Common Mistakes
Mistake: Confusing quintillion with quadrillion or sextillion because the names sound similar.
Correction: Remember the order: million (6 zeros), billion (9), trillion (12), quadrillion (15), quintillion (18), sextillion (21). Each step adds 3 more zeros.