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How Many Zeros in a Sexdecillion?

How many zeros in a sexdecillion? A sexdecillion has 51 zeros: 1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000, or 1051 in scientific notation. It is the 16th term in the short-scale "-illion" series used in the United States and modern British English. Learn more about how many zeros does a unvigintillion have.

A sexdecillion has

51

zeros

Written Form
1 followed by 51 zeros
Scientific
10⁵¹

The Sex- Prefix and Sexdecillion's Position

The direct answer: exactly 51 zeros. The prefix sex- means six, combined with dec- for ten, giving the 16th position (sex + dec = sixteen). The zero count follows the standard formula: the nth "-illion" has 3n + 3 zeros, so 3 × 16 + 3 = 51. See also: Quadrillion zeros.

How many zeros in a Sexdecillion? 51 zeros, written as 1 followed by 51 zeros (10⁵¹).
How many zeros in a Sexdecillion? — howmanyzeros.org

Sexdecillion's Position in the Sequence

Comes after
Quindecillion — 1048
Comes before
Septendecillion — 1054

The step from one named number to the next always adds three zeros in the short scale, so knowing the zero count for any one name makes the surrounding ones trivial to derive.

Sexdecillion vs Its Neighbors

Sexdecillion's position in the short-scale sequence.
NameZerosScientific notation
Quindecillion481048
Sexdecillion511051
Septendecillion541054

How Many Zeros in 100 Sexdecillion?

  • 1 sexdecillion = 1051 — 51 zeros
  • 100 sexdecillion = 1053 — 53 zeros
  • 1,000 sexdecillion = 1054 — 54 zeros (= one septendecillion)

Whether you're working with a billion or a sexdecillion, multiplying by 10 always adds one zero, and multiplying by 1,000 always advances you to the next named number.


Zeros in a Sexdecillion: FAQ

What comes before a sexdecillion?
Quick answer

Hundred quindecillion comes right before a sexdecillion.

What comes after a sexdecillion?
Quick answer

Ten sexdecillion comes next, followed by hundred sexdecillion and then septendecillion.

How many digits does a sexdecillion have?

A sexdecillion has 52 digits in total — that's the digit 1 followed by 51 zeros.

How many zeros in 2 sexdecillion? In half a sexdecillion?

Two sexdecillion keeps the same 51 zeros. Half a sexdecillion has 50 trailing zeros after the 5.

Is a 51-digit number always a sexdecillion?

No. A 51-digit number tops out at hundreds of quindecillions — a sexdecillion is the first 52-digit number.

How many zeros in a sexdecillion in the British system?

Under the old long-scale system, a sexdecillion meant 1096 — nearly double today's short-scale value.