Something you all have failed to realize is that none of the numbers exist.
Yes. That's right. Not 0, nor 1, nor -2, nor 893, 2.445 or 3.14159265349798...
You see, all mathematics is simply a model. That's why we have things like an endless decimal in pi and e, as well as other irrationals. In fact, 0 is somewhat of an idealistic number. It's a member of the set we call Rationals, defined as all numbers that can be expressed as a fraction of 2 integers (including 0 and negatives, with the exception of not 0 in the denominator, of course). The fact that we can express these numbers so succinctly is evidence to the fact that it's inherently inaccurate. Maybe just a smidgen, but it is. In fact, you will never encounter a single rational number in the real world in your entire existence. It can be proven mathematically. Irrational numbers are infinitely more dense on the number line than Rationals. Therefore, there is probability 1 that a number picked at random will be Irrational. The universal constants that we have to work around, such as pi and Euler's number (both of which are Irrational), have no great expressions in our number representation system, and this is due to that simple fact: all numbers are intellectual concepts created by man to help him understand what's going on around him. No, you can't divide by 0, but that's not 0's fault. It's man's fault for using such a problematic system.
I'll illustrate this using fruit. Let's say I have 4 apples. If I know I have 4 apples, that means I am using the concept of the number 4 to help me understand how many apples there are. If your definition of existence is that it lives in the minds of man (see the Platonic Forms, and the third tier of his pyramid--first the Good, then the Forms, then mathematical and grammatical concepts), then yes, Four exists. And so does Zero, and so does Grandelflfljjjssshargensmarg, because I just made it up (it means a very big sneeze). If your definition of existence is that its existence (or nonexistence) does not derive from its perception (or lack of perception) in the minds of those perceiving it, then no, none of the numbers exist. And neither does the concept of school, the internet, or government.
Let's think of it this way: If I have 4 apples, and I can look at them and see that there are 4. But let's say we don't exist. There is no one there to perceive there being 4 apples. How could the concept of 4 still exist, without someone to understand it? Each apple exists, yes, but it takes a point of view to see there being 4.
Still don't believe me? Well even if you don't agree with the rest of my statements, you have to agree that numbers are inherently inaccurate. Saying "I have 4 apples" is fine for conversation, but that leaves out important bits of information:
Are they all Granny Smith Apples?
Yes. I have 4 Granny Smith Apples.
OK, well are they all ripe?
Yes. I have 4 ripe Granny Smith Apples.
OK, well did they all come from the same tree?
Yes. I have 4 ripe Granny Smith Apples from the second tree on the left as you come to the Johnsons' orchard.
...
And the conversation could continue, to the point that they obviously cannot occupy the same space, and be made up of the same atoms. This proves that unless you describe each apple individually (without a concept of numbers), you cannot include all the information, even using the concept of the whole number 4 applied to a fairly simple-looking real-world problem.
My point: numbers do not exist.