One Zillion- Understanding Large Numbers

What Is One Zillion?

One zillion is not a real number. It's a made-up term people use when they want to say an impossibly large number without getting into specific math.

You already knew that. But here's what most people don't know: zillion is not part of any official number sequence. It never was. Numbers like million, billion, trillion go up in groups of three zeros. Zillion doesn't follow that pattern.

Mathematicians call made-up number names nonce words. They're words that exist only in informal speech. You won't find zillion in any dictionary as a real number.

What Comes After Trillion?

Real large numbers follow a precise naming system. After trillion comes:

• Quadrillion (4 groups of zeros)
• Quintillion (5 groups of zeros)
• Sextillion (6 groups of zeros)
• Septillion (7 groups of zeros)
• Octillion (8 groups of zeros)
• Nonillion (9 groups of zeros)
• Decillion (10 groups of zeros)

The pattern is Latin number + ion. Quadrillion is 4 groups of zeros. Quintillion is 5 groups. And so on.

The Short Scale vs Long Scale

Here's where it gets messy. Short scale countries (US, UK, most English-speaking nations) use groups of three zeros. Long scale countries (most European nations) use groups of six zeros.

Short scale: million = 10^6, billion = 10^9, trillion = 10^12

Long scale: million = 10^6, billion = 10^12, trillion = 10^18

The difference matters when you're talking about real numbers used in finance and science. Most people don't care. You should anyway.

What Is the Biggest Real Number Name?

Beyond centillion, there's googol (10^100). Beyond googol is googolplex (10^10^100). These are real mathematical terms.

Googolplex is so large that if you tried to write it out as zeros, you couldn't fit the universe with the paper. That's not an exaggeration. That's math.

Beyond that, mathematicians have googolplexian (10^10^10^100). And beyond that, there's just theoretical higher numbers that don't have practical use.

How To Use Large Number Names

Getting Started:

Using large number names in conversation is simple. You use them when you want to sound specific about large quantities.

Example: "The national debt is over 30 trillion dollars." That's a real number being used in a real context. You can look up the exact figure on government websites.

Example: "That company is worth over 2 trillion dollars." That's a real number being used in a real context. You can look up market cap figures on financial websites.

Example: "That software company is worth over 2 trillion dollars." That's a real number being used in a real context. You can look up market cap figures on financial websites.

Using made-up large number names is different. You use them when you want to sound vague about impossibly large quantities.

Example: "I have one zillion reasons to say no." That's informal speech. You won't find that in formal writing.

Comparing Large Number Names

Why Zillion Sounds Like a Real Number

Zillion sounds real because it follows the pattern of ion words. Million, billion, trillion, quadrillion, quintillion, sextillion, septillion, octillion, nonillion, decillion, uncentillion, duocentillion, trescentillion, etc.

The pattern goes: number + ion. Zillion follows that pattern. It looks like it should be the next number in sequence.

But it's not. Zillion was invented as slang for an impossibly large number. It was never part of the official sequence.

What Is the Next Real Number After Centillion?

After centillion comes ducentillion (10^603). After that comes trecentillion (10^903). The pattern goes by Latin numbers: un, duo, tres, quattuor, etc.

These numbers are so large that they don't have practical use outside of mathematical theory. You won't encounter them in everyday life.

Most people stop at vigintillion (10^63) when they want to sound smart about impossibly large numbers. Beyond that, it's just showing off.