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How Many Zeros in a Septendecillion?

How many zeros in a septendecillion? A septendecillion has 54 zeros in the short-scale system: 1054. The name comes from the Latin septendecim, meaning seventeen — the 17th "-illion" name after a million. See also: How many zeros does a duovigintillion have.

A septendecillion has

54

zeros

Written Form
1 followed by 54 zeros
Scientific
10⁵⁴

Septendecillion's Position in the Sequence

The direct answer: exactly 54 zeros. It sits between sexdecillion (1051) and octodecillion (1057) in the short-scale chain. Related: Million zeros.

How many zeros in a Septendecillion? 54 zeros, written as 1 followed by 54 zeros (10⁵⁴).
How many zeros in a Septendecillion? — howmanyzeros.org

Septendecillion Written Out

Written in full, one septendecillion is the digit 1 followed by 54 zeros: 1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 — 55 digits in total. In the standard naming pattern, every name after million adds three zeros to the previous one: 3 × 17 + 3 = 54.

Short Scale vs Long Scale: One Septendecillion

The value of septendecillion differs enormously by convention.
SystemZerosScientific notation
Short scale (US / modern UK)541054
Long scale (continental Europe)10210102

How Many Zeros in 1,000 Septendecillion?

  • 1 septendecillion = 1054 — 54 zeros
  • 10 septendecillion = 1055 — 55 zeros
  • 1,000 septendecillion = 1057 — 57 zeros (= one octodecillion)

The long-scale septendecillion is 1048 times larger than the short-scale one — a difference equal to one quindecillion — which is why the name is rarely used in international scientific writing. Learn more about zeros in a novemdecillion.


Zeros in a Septendecillion: FAQ

What comes before a septendecillion?
Quick answer

Hundred sexdecillion comes right before a septendecillion.

What comes after a septendecillion?
Quick answer

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

How many digits does a septendecillion have?

A septendecillion has 55 digits in total — that's the digit 1 followed by 54 zeros.

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

Two septendecillion keeps the same 54 zeros. Half a septendecillion has 53 trailing zeros after the 5.

Is a 54-digit number always a septendecillion?

No. A 54-digit number tops out at hundreds of sexdecillions — a septendecillion is the first 55-digit number.

How many zeros in a septendecillion in the British system?

Under the old long-scale system, a septendecillion meant 10102 — 48 more zeros than today's short-scale septendecillion.