How Many Zeros in a Septillion?
The Short Answer a septillion has 24 zeros in the U.S. numbering system.
It’s written as: 1,000,000,000,000,000,000,000,000
Scientific notation: 10^24
What Is a Septillion?
"Sept-" means seven, making septillion the seventh number in the "illion" series:
- Million – 106
- Billion – 109
- Trillion – 1012
- ... to Septillion – 1024
It’s rarely used outside of very large scientific data sets or theoretical computations.
How to Write a Septillion
In full numeric form: 1,000,000,000,000,000,000,000,000
That’s a 1 followed by 24 zeros.
Septillion Comparison Table
| Number Name | Value | Zeros |
|---|---|---|
| Million | 1,000,000 | 6 |
| Billion | 1,000,000,000 | 9 |
| Trillion | 1,000,000,000,000 | 12 |
| Quadrillion | 1,000,000,000,000,000 | 15 |
| Quintillion | 1,000,000,000,000,000,000 | 18 |
| Sextillion | 1,000,000,000,000,000,000,000 | 21 |
| Septillion | 1,000,000,000,000,000,000,000,000 | 24 |
Questions & Answers
What is the abbreviation of septillion?
The common abbreviation for septillion is "sep". In mathematical notation, it’s often referred to as 1024.
How many zeros in 2 septillion?
2 septillion = 2,000,000,000,000,000,000,000,000
That’s a 2 followed by 24 zeros.
How many zeros in 10 septillion?
10 septillion = 10,000,000,000,000,000,000,000,000
That’s a 1 followed by 25 zeros.
How many zeros in 100 septillion?
100 septillion = 100,000,000,000,000,000,000,000,000
That’s a 1 followed by 26 zeros.
How many zeros in half a septillion?
0.5 septillion = 500,000,000,000,000,000,000,000
That’s a 5 followed by 23 zeros.
What Comes Before Septillion?
The number that comes before a septillion is a sextillion.
- Sextillion = 1,000,000,000,000,000,000,000 (that’s 21 zeros)
- It’s written as 10²¹ in scientific notation
A septillion is a thousand sextillions.
What Comes After Septillion?
The next number after a septillion is an octillion.
- Octillion = 1,000,000,000,000,000,000,000,000,000 (that’s 27 zeros)
- It’s written as 10²⁷
An octillion is a thousand septillions.
Quick Comparison Chart
| Name | Number of Zeros | Scientific Notation |
|---|---|---|
| Sextillion | 21 | 1021 |
| Septillion | 24 | 1024 |
| Octillion | 27 | 1027 |
How many digits does a septillion have?
A septillion has 25 digits in total — that’s the digit 1 followed by 24 zeros.
Is a 24-digit number a septillion?
Not quite. A 24-digit number is just under a septillion. A true septillion is 1 followed by 24 zeros, which makes it a 25-digit number in total.
How many zeros in a septillion in the British system?
In the British long scale (historically), a septillion means 1 followed by 42 zeros — 10^42. But in modern usage (including UK), the short scale is adopted: 1 followed by 24 zeros.
Real-World Context
- Rarely used in real-world measurements
- May appear in estimates involving subatomic particle counts or large-scale data modeling
Septillion Summary
- Septillion = 1 followed by 24 zeros
- Scientific notation:
10^24 - Larger than sextillion, smaller than octillion
Although rarely used, septillion is a powerful example of exponential growth and the vast scale numbers can reach in theoretical and computational sciences.
Related pages:
- How Many Zeros in a Thousand?
- How Many Zeros in a Million?
- How Many Zeros in a Billion?
- How Many Zeros in a Trillion?
- How Many Zeros in a Quadrillion?
- How Many Zeros in a Quintillion?
- How Many Zeros in a Sextillion?
- How Many Zeros in a Septillion?
- How Many Zeros in a Octillion?
- How Many Zeros in a Nonillion?
- How Many Zeros in a Googol?
- How Many Zeros in a Googolplex?