It isn't shaped like anything because the US has never printed any bills higher than $100,000. Anything that says $1 million is a novelty item or outright fake.
Regardless of the series letter, $65 in worn condition, up to about $100 in nearly-new shape.
In worn condition, $15 or so. In better shape it might retail for up to $35.
A million sided shape shape is called a megagon.
In worn condition it's only worth face value. In better shape it might retail for up to $70. Despite their age, most series-1950 $50 bills are not scarce. $50 was a considerable amount of money in the 1950s so (relatively) high-denomination bills didn't see a lot of circulation.
There is no "most" with respect to polygons. You could make a shape with a million sides, and then make a new shape with a million and one, and keep going forever.
A shape with a million sides.
A million sided shape is called a Megagon.
The Rectangle.
Round?
The value of a 1934 G series $10 bill from the Federal Reserve Bank of Chicago can vary depending on its condition and any unique characteristics. However, generally speaking, these bills are considered common and their value typically ranges from around $15 to $40 in circulated condition. Bills in better condition or those with unusual attributes can potentially be worth more to collectors.
pentigonon
a shape with one million sides