There are different naming conventions for numbers used around the world. This system is used in the United States and most scientific communities:

Number of zeros(ex. 10^x)   /    Names (USA & Scientific)

3       thousand
6       million
9       billion
12      trillion
15      quadrillion
18      quintillion
21      sextillion
24      septillion
27      octillion
30      nontillion
33      decillion
36      undecillion
39      duodecillion
42      tredecillion
45      quattudecillion
48      quidecillion
51      sexdecillion
54      septendecillion
57      octodecillion
60      novemdecillion
63      vigintillion
66      unvigintillion
69      dovigintillion
72      trevigintillion
75      quattuvigintillion
78      quinvigintillion
81      sexvigintillion
84      septenvigintillion
87      octovigintillion
90      novemvigintillion
93      trigintillion
96      dotrigintillion
99      dotrigintillion
102     tretrigintillion
105     quattutrigintillion
108     quintrigintillion
111     sextrigintillion
114     septentrigintillion
117     octotrigintillion
120     novemtrigintillion
.
.
.
303     centrillion


There is also a googol, which has 100 zeros (ten dotrigintillion), and a googolplex, which has a googol zeros (10^100 zeros).
A zillion, while commonly used to represent a number with many zeros, does not have an actual value.