That was a good explanation, AHunter3. For Graham’s number- whoo boy, I don’t have those years of mathematical education yet.

The number thing others have answered more or less accurately. I just want to pick a bit of a nit about the source of the name “google”. Yes, the gloss of googol as a large number is intended (with respect to the amount of results returned), but it also refers to google, a deprecated form of goggle: “To turn the eyes to one side or other, to look obliquely, to squint”. That is, it looks at a lot of different things in all sorts of directions.

How about the second Skewes Number which equals 10[sup]10[sup]10[sup]10[sup]3[/sup][/sup][/sup][/sup]?

Compared to Skewes Number[sub]2[/sub] a googolplex (10[sup]10[sup]10[sup]2[/sup][/sup][/sup]) is virtually zero.

I have way too much time on my hands, it would seem.

OK, here’s one you could count to without hitting unnamed numbers (if it weren’t for mortality and the heat death of the universe and stuff like that):

Nine hundred ninety nine centillion nine hundred ninety nine novemnonagintillion nine hundred ninety nine octononagintillion nine hundred ninety nine septemnonagintillion nine hundred ninety nine sexnonagintillion nine hundred ninety nine quintnonagintillion nine hundred ninety nine quattuornonagintillion nine hundred ninety nine trenonagintillion nine hundred ninety nine duononagintillion nine hundred ninety nine unnonagintillion nine hundred ninety nine nonagintillion nine hundred ninety nine nine hundred ninety nine novemoctogintillion nine hundred ninety nine octooctogintillion nine hundred ninety nine septemoctogintillion nine hundred ninety nine sexoctogintillion nine hundred ninety nine quintoctogintillion nine hundred ninety nine quattuoroctogintillion nine hundred ninety nine treoctogintillion nine hundred ninety nine duooctogintillion nine hundred ninety nine unoctogintillion nine hundred ninety nine octogintillion nine hundred ninety nine novemseptuagintillion nine hundred ninety nine octoseptuagintillion nine hundred ninety nine septemseptuagintillion nine hundred ninety nine sexseptuagintillion nine hundred ninety nine quintseptuagintillion nine hundred ninety nine quattuorseptuagintillion nine hundred ninety nine treseptuagintillion nine hundred ninety nine duoseptuagintillion nine hundred ninety nine unseptuagintillion nine hundred ninety nine septuagintillion nine hundred ninety nine novemsexagintillion nine hundred ninety nine octosexagintillion nine hundred ninety nine septemsexagintillion nine hundred ninety nine sexsexagintillion nine hundred ninety nine quintsexagintillion nine hundred ninety nine quattuorsexagintillion nine hundred ninety nine tresexagintillion nine hundred ninety nine duosexagintillion nine hundred ninety nine unsexagintillion nine hundred ninety nine sexagintillion nine hundred ninety nine novemquinquagintillion nine hundred ninety nine octoquinquagintillion nine hundred ninety nine septemquinquagintillion nine hundred ninety nine sexquinquagintillion nine hundred ninety nine quintquinquagintillion nine hundred ninety nine quattuorquinquagintillion nine hundred ninety nine trequinquagintillion nine hundred ninety nine duoquinquagintillion nine hundred ninety nine unquinquagintillion nine hundred ninety nine quinquagintillion nine hundred ninety nine novemquadragintillion nine hundred ninety nine octoquadragintillion nine hundred ninety nine septemquadragintillion nine hundred ninety nine sexquadragintillion nine hundred ninety nine quintquadragintillion nine hundred ninety nine quattuorquadragintillion nine hundred ninety nine trequadragintillion nine hundred ninety nine duoquadragintillion nine hundred ninety nine unquadragintillion nine hundred ninety nine quadragintillion nine hundred ninety nine novemtrigintillion nine hundred ninety nine octotrigintillion nine hundred ninety nine septemtrigintillion nine hundred ninety nine sextrigintillion nine hundred ninety nine quinttrigintillion nine hundred ninety nine quattuortrigintillion nine hundred ninety nine tretrigintillion nine hundred ninety nine duotrigintillion nine hundred ninety nine untrigintillion nine hundred ninety nine trigintillion nine hundred ninety nine novemvigintillion nine hundred ninety nine octovigintillion nine hundred ninety nine septemvigintillion nine hundred ninety nine sexvigintillion nine hundred ninety nine quintvigintillion nine hundred ninety nine quattuorvigintillion nine hundred ninety nine trevigintillion nine hundred ninety nine duovigintillion nine hundred ninety nine unvigintillion nine hundred ninety nine vigintillion nine hundred ninety nine novemdecillion nine hundred ninety nine octodecillion nine hundred ninety nine septemdecillion nine hundred ninety nine sexdecillion nine hundred ninety nine quintdecillion nine hundred ninety nine quattuordecillion nine hundred ninety nine tredecillion nine hundred ninety nine duodecillion nine hundred ninety nine undecillion nine hundred ninety nine decillion nine hundred ninety nine nonillion nine hundred ninety nine octillion nine hundred ninety nine septillion nine hundred ninety nine sextillion nine hundred ninety nine quintillion nine hundred ninety nine quadrillion nine hundred ninety nine trillion nine hundred ninety nine billion nine hundred ninety nine million nine hundred ninety nine thousand nine hundred ninety nine.

Still expressible in exponential notation. Not a contender.

It’s easier if you use bigger numbers. Try this on for size:

Aleph-null bottles of beer on the wall,

Aleph-null bottles of beer

Take one down and pass it around

Aleph-null bottles of beer on the wall

At least, if you accept “aleph-null” as a number. But if you do, then it’s still not the largest number, since you’d then also have to accept aleph-one, aleph-two, aleph-centillion, etc., and there are other “numbers” which are bigger than any aleph, and so on.

Nobody would do that. Because NurseCarmen’s number is bor’s number times two.

Well, as we know, if we divide 1 by smaller and smaller numbers, we get larger and larger numbers. So we divide one by zero for a very, very, *very * large number.

“But that is mathematically impossible!”, you would say.

Ahhhhh, but here’s the beauty of it: We take the result and subtract 1.

((1/0) - 1)

And we name it “plynck’s constant”.

Yep, got it all figured out, and before dinner, too

Meh. After the first duodecillion beers or so, who gives a crap anymore?

Are there any rational numbers not expressible in exponential notation? Irrational numbers being not expressible at all in digits, only their approximations.

And we really need to find help for **AHunter3**

When you’re dealing with large numbers, “expressible” seems to be taken as a synonym for “intelligibly expressible”. Graham’s number, for instance, is expressible in exponential notation, but not in any meaningful way.

Infinity is certainly an established name.

A Googleplex is probably the highest commonly known number.

Graham’s Number appears to be the highest number that’s ever been actually used.

The Moser appears to be the highest definable number.

999 vigintillion 999 novemdecillion 999 octodecillion 999 septemdecillion 999 sexdecillion 999 quintdecillion 999 quattuordecillion 999 tredecillion 999 duodecillion 999 decillion 999 nonillion 999 octillion 999 septillion 999 sextillion 999 quintillion 999 quadrillion 999 trillion 999 billion 999 million 999 thousand 999 is the highest number that could theoretically be counted to (as in all numbers less than it would have a name).

But infinity isn’t a number.

How do you figure? It looks like **AHunter3** has counted quite a bit higher than you…

Correct me if I’m wrong, but I’m pretty sure the unmodified word “number” has no formal definition in mathematics, so you can’t really pin down whether something is or is not a “number”—it depends on what kind of numbers or what set of numbers you’re talking about.

I think most of the posts so far have assumed the OP was asking about the biggest **real** number—a natural assumption, since the set of real numbers (or perhaps some subset thereof) is what most of us think of when we think of “numbers.” And yes, infinity is not a real number. But if you allow things like transfinite numbers (as **Chronos** mentioned), that’s a whole new ball game, and you can easily get “bigger” numbers than any of the real numbers mentioned.

**Little Nemo** is correct if we confine ourselves to officially accepted names. The other names are considered logical extensions of the official naming convention (“considered” meaning "by people other than just me, i.e., I didn’t just make them up or anything

I have no idea why the official named series stops at the vigintillion mark.

But it doesn’t refer to anything specific; in fact, I don’t think it means anything out of context.

It may the highest number that anyone’s bothered to define, but simply definining a k-Moser as (Moser)[sup]k[/sup] gives you a lot of larger, defineable numbers.

Chronos did add the proviso that you need to accept transfinite “numbers” as numbers - I don’t. The don’t obey rules of addition, subtraction etc. as far as I can tell or the rule of succession that tells us how to form members of the set.

I wouldn’t be surprised to be wrong about this but that’s my story until a mathematician comes along to show that such entities do follow such rules.