Gazilion isn't a real number, however this might help :)
Billion has 9 zeros
Trillion has 12 zeros
Quadrillion has 15 zeros
Quintillion has 18 zeros
Sextillion has 21 zeros
Septillion has 24 zeros
Octillion has 27 zeros
Nonillion has 30 zeros
Decillion has 33 zeros
Undecillion has 36 zeros
Duodecillion has 39 zeros
Tredecillion has 42 zeros
Quattuordecillion has 45 zeros
Quindecillion has 48 zeros
Sexdecillion has 51 zeros
Septendecillion has 54 zeros
Octodecillion has 57 zeros
Novemdecillion has 60 zeros
Vigintillion has 63 zeros
Googol has 100 zeros.
Centillion has 303 zeros ( in Britain, it has 600 zeros)
Googolplex has a googol of zeros
Imagine trying to write them out...
999 gazilion
10000000000000 billlion gazilion bagilion hazilion playa
Here is the problem. There is really no such number as a gazillion. It is an expression used to mean a really big number. For example, we say that are a gazillion reasons not to do homework right now and one of them is to answer really fun wiki answers questions and we know there are a gazilion of those to answer. So there is nothing that can come after a number that does not exist. Another example of this is a bazillion which also is not really a number. One thing is sure about these non-numbers, if you answer a gazillion-billion wiki answer question you will know a lot, and you will be a ruby contributor. You may even win some wiki prizes!