How Many Zeros in a Jillion?

Is a Jillion a Real Number?

No — a jillion is not a real number. Real named large numbers have precise, mathematically agreed definitions: a million is exactly 106, a trillion exactly 1012, a googol exactly 10100. Jillion has none of these properties. Questions about why a googolplex cannot be written out are answered in how many zeros does a googolplex have.

How Does Jillion Compare to Zillion, Gazillion, and Bazillion?

All four are informal non-numbers with undefined values. In everyday use, speakers sometimes arrange them in an informal size order based purely on how large they feel, but there is no mathematical basis for this ranking.

A vigintillion is exactly 10⁶³; a jillion is whatever the speaker means when they can't be bothered to name a specific amount.

Where Did the Word "Jillion" Come From?

• Emerged in American English in the 1940s
• The "j-" prefix was chosen for its playful sound, like "z-" in zillion or "g-" in gazillion
• Owes its feel of largeness entirely to the borrowed "-illion" suffix

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Zeros in a Jillion: FAQ

Is a jillion a real number?

Quick answer

No — it has no exponent, no scientific notation, and no place in any mathematical standard.

When did "jillion" first appear?

Quick answer

Around 1940, in American English. For more on gazillion in Calvin and Hobbes, see zeros in a gazillion.

Is a jillion bigger than a zillion?

There's no formal answer — both are undefined; any ranking is purely a matter of how emphatic the word feels.

What real number should I use instead of "jillion"?

If you need precision, use a formally defined number — million through centillion, or googol for something truly enormous.

Does "jillion" appear in any dictionary?

Yes, as an informal noun meaning "an extremely large but unspecified number" — without a numerical definition.