Could someone recomend a book on number theory that uses a lot of group theory and algebra to explain results? Like for example the proof that mod that is a prime power has a primitive root is simple if we observe $\mathbb Z\_{p^\alpha}^{\times}\cong \mathbb Z\_{(p-1)p^{\alpha-1}}$. Also noticin half of the elements $\bmod p$ are quadratic residues is immediate if we look at it as a cyclic group. Or as a final example fermat and euler are immediate consequences of lagrange.

I'm looking for a book that treats results from this perspective.

Thank you very much in advance.

Regards.