Best way to clean up mesh? I used the Boolean tools to subtract one mesh to another and thus create this mesh.

The result is not very clean. How can I do to best clean this result and get a nice smooth surface?
Do I need to re-arrange the vertex one by one, or is there a faster, simpler and more effective solution?
The easiest way to fix this problem is to select the object, and go to properties editor -&gt; object data properties -&gt; normals and enable auto-smooth with an angle of 30 degrees or more:
.