How many stereoisomers are there?

2ⁿ

A stereocenter or stereogenic center represents an atom bearing groups and an interchanging of any two groups forms a stereoisomer.  It is important to know that a molecule can have multiple stereocenters, in the end forming many stereoisomers.According to Wikipedia, in compounds whose stereoisomerism is due to tetrahedral stereogenic centers, the total number of stereoisomers will not exceed 2ⁿ.  What does n mean?  Well, n is the number of tetrahedral stereocenters.  Moreover, molecules with symmetry frequently have fewer than the maximum possible number of stereoisomers.