How Many Zeros in a Centillion?

Centillion's Position as the 100th "-illion"

The direct answer: exactly 303 zeros. The short-scale formula confirms it: the 100th "-illion" after a million gives 3 × 100 + 3 = 303 zeros — the endpoint of the systematic Latin-prefix naming chain in the short-scale US system.

What Does 1 Centillion Look Like?

Writing out one centillion in full requires placing the digit 1 and then writing 303 zeros — a task that, printed at normal font size, would span several pages. The number contains 101 groups of three digits. To see the digit 1 followed by 24 zeros and 10²⁴ in scientific notation, read septillion zeros.

A centillion dollars exceeds the total wealth of every person on Earth (roughly 10¹³) by 290 orders of magnitude — an entirely abstract concept rather than a financial quantity.

Is Centillion the Biggest Named Number?

Centillion is the largest number with a standard "-illion" name in most English dictionaries, but it's far from the largest number with any name at all. For more on observable-universe atom estimates, see zeros in an undecillion.

So the ordering is: googol < centillion < googolplex < googolplexian. The naming sequence beyond centillion can in principle continue (uncentillion, duocentillion, and so on), but these names are not in standard dictionaries.

How Many Zeros in 10 Centillion and 100 Centillion?

• 1 centillion = 10303 — 303 zeros
• 10 centillion = 10304 — 304 zeros
• 100 centillion = 10305 — 305 zeros

Long-Scale Centillion

Short scale

10303 — 303 zeros

Long scale

10600 — 600 zeros, exactly double the short-scale exponent

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Zeros in a Centillion: FAQ

What comes before a centillion?

Quick answer

The number directly before a centillion is 10300 — 300 zeros, one thousand times smaller than a centillion. Its systematic "-illion" name (the 99th in the sequence) isn't found in standard dictionaries the way centillion is.

What comes after a centillion?

Quick answer

Ten centillion comes next (10³⁰⁴), followed by one hundred centillion (10³⁰⁵), which has two more zeros than one centillion.

How many digits does a centillion have?

A centillion has 304 digits in total — that's the digit 1 followed by 303 zeros.

How many zeros in half a centillion?

Half a centillion has 302 trailing zeros after the 5 — one fewer than a full centillion.

Is centillion bigger than a googol?

Yes. A googol (10¹⁰⁰) has only 100 zeros, making it far smaller than a centillion's 303 zeros.

How many zeros in a centillion in the British system?

Under the old long-scale system, a centillion meant 10600 — exactly double today's short-scale value.