What does the number of the us senators in the congress represent?

It represents 2 senators for each State. This method means that each State gets an equal voice in the Senate.

On the other hand, the number of Representatives is by how many people live in a particular State. This method means that each person, or group of persons get an equal voice in the House.

The above represents a compromise by the fathers of our country, some of whom thought that the States should rule the Federal government, and some of whom thought that the people should directly rule the Federal government. This scheme is also yet another one of the many checks and balances in the US government.