How Many Zeros in a Sextillion?
How many zeros in a sextillion? A sextillion has 21 zeros, written as 1,000,000,000,000,000,000,000 or 1021 in scientific notation. This is the standard short-scale definition used in the United States and modern British English — seven groups of three zeros placed after the leading 1. Related: How many zeros in a hundred.
A sextillion has
21
zeros
- Written Form
- 1 followed by 21 zeros
- Scientific
- 10²¹
Sextillion's Position on the Short-Scale Ladder
The short answer: exactly 21 zeros. The prefix sex- is Latin for six, referring to sextillion's position as the sixth named step above a million. A sextillion is one thousand times larger than a quintillion, which itself has 18 zeros. See also: Zeros in a quadrillion.
How to Write a Sextillion
- Standard form
1,000,000,000,000,000,000,000- Scientific notation
1021- Words
- one sextillion, or one thousand quintillion
Zeros in Quintillion, Sextillion, and Septillion
Sextillion occupies the seventh named position in the short-scale sequence, counting from million. Each step multiplies the previous value by exactly one thousand.
| Name | Zeros | Scientific notation |
|---|---|---|
| Quintillion | 18 | 1018 |
| Sextillion | 21 | 1021 |
| Septillion | 24 | 1024 |
Real-World Examples
At the sextillion scale, physical quantities in science start to appear regularly.
The total number of atoms in the human body is estimated at around 7 sextillion — 7 × 1021.
The mass of Earth's oceans, expressed in individual drops of water, also reaches into the sextillion range — the kind of count where scientific notation stops being a convenience and becomes a necessity.
- 1 sextillion = 1,000 quintillion
- 1 sextillion = 1 billion trillion (109 × 1012)
- 1 sextillion = 1,000,000 quadrillion
How Many Zeros Does a Long-Scale Sextillion Have?
In the older long-scale system — still used in some European countries and historically used in the UK before the 1970s — a sextillion represents a completely different number: 1036, or 1 followed by 36 zeros.
The long scale defines each new "-illion" as the previous one multiplied by one million rather than one thousand, so long-scale sextillion = (106)6 = 1036. By contrast, the short-scale sextillion = 1021 — a gap of 15 orders of magnitude for the exact same word. Learn more about zeros in a centillion.
Zeros in a Sextillion: FAQ
What is the abbreviation of sextillion?
There's no standard financial shorthand for sextillion the way "1B" stands for a billion — figures rarely reach this scale outside of scientific and astronomical contexts, where scientific notation (1021) is used instead.
What comes before a sextillion?
Quick answer
Hundred quintillion comes right before a sextillion.
What comes after a sextillion?
Quick answer
Ten sextillion comes next, followed by hundred sextillion and then septillion.
How many digits does a sextillion have?
A sextillion has 22 digits in total — that's the digit 1 followed by 21 zeros.
How many zeros in 2 sextillion? In half a sextillion?
Two sextillion keeps the same 21 zeros. Half a sextillion — 500,000,000,000,000,000,000 — has 20 trailing zeros after the 5.
Is a 21-digit number always a sextillion?
No. A 21-digit number ranges from 100,000,000,000,000,000,000 to 999,999,999,999,999,999,999 — that's hundreds of quintillions, not a sextillion. A sextillion is the first 22-digit number.
How many zeros in a sextillion in the British system?
Under the old British long-scale system, a sextillion meant 1036 — 15 more zeros than today's short-scale sextillion. Modern British English now matches US usage at 21 zeros.