About 2

I write trivia about 2 

 Jupiter is smaller each year 2cm.

 

Now, let us look one from a mathematical point of view.

2 is well known and is the smallest prime number.

In addition, it is only one prime without the spelling e.

 

２：two

３：three

5：five
7：seven
11：eleven
13:thirteen
17:seventeen

...

In addition to　"Euler's polyhedron formula"
When it is three-dimensional polyhedron
(Number of Faces)−(Number of Edges)＋(Number of Vertices)=２