What is the name of a 3000000 side 2d shape?

A 2D shape with 3,000,000 sides is called a myriagon. The prefix "myria-" denotes 10,000, so a myriagon has 10,000 sides. In geometric terms, a myriagon is a polygon with 3,000,000 sides, each of equal length and internal angles adding up to 180 degrees. It is a very rare and complex shape in mathematics.