There is no official metric prefix for ten million, nor is there a Greek prefix that would work really well. In this case, you can go with the conventional n-gon format and call it a 10,000,000-gon ("ten million"=gon).
The name of a 12 sided polygon is Dodecagon.
A 8 sided polygon is called a octagon.
The name of a 9 sided polygon is Nonagon.
The name of a 19 sided polygon is enneadecagon.
The name of a 17 sided polygon is Heptadecagon.
a bigdickogram
The name of a 12 sided polygon is Dodecagon.
name of 4000 sided polygon
A 8 sided polygon is called a octagon.
The name of a 9 sided polygon is Nonagon.
The name of a 19 sided polygon is enneadecagon.
The name of a 17 sided polygon is Heptadecagon.
The name of a 8 sided polygon is Octagon.
The name of a 10 sided polygon is Decagon.
The name of a 14 sided polygon is Tetradecagon.
The name of a 99 sided polygon is enneacontaenneagon.
The name of a 18 sided polygon is Octadecagon.