Can there be involutions in the unit group of $\mathbb{Z}_n$?
112390
Solutions of $x^2 \equiv 1 \pmod N$
114916
$\mathbb Z_{mn}$ isomorphic to $\mathbb Z_m\times\mathbb Z_n$ whenever $m$ and $n$ are coprime
47522
group generators of $(\mathbb Z_{17}-\{0\},\times)$
9794
Quotient ring of Gaussian integers $\mathbb{Z}[i]/(a+bi)$ when $a$ and $b$ are NOT coprime
126930
Finding all group homomorphisms of $S_n\to\mathbb{C}^*$ and $A_n\to\mathbb{C}^*$
13761
Automorphisms in $\mathbb{Z}_n$
68915
What are the units in $\mathbb{Z}[\root 3 \of 2]$?
26661
Ring homomorphisms from $\mathbb{Z}_n$ to $\mathbb{Z}_m$
26749
$\mathbb{Z}[X]/(X^2-1)$ is not isomorphic with $\mathbb{Z}\times \mathbb{Z}$
137739
Prove that the group isomorphism $\mathbb{Z}^m \cong \mathbb{Z}^n$ implies that $m = n$
129827
Product of invertibles in $\Bbb Z_n$ [Wilson's Theorem generalization]
119648
For which $n$ and $k$ are there nontrivial homomorphisms from $S_n$ to $\mathbb{Z}/k\mathbb{Z}$?
93681
Integral closure of $\mathbb{Z}$ in $\mathbb{C}$ is not finitely generated as a $\mathbb{Z}$-module?
119052
Finding invertible elements in $\mathbb{Z}/m\mathbb{Z}$
138026
To show that $n!f(x) \in \mathbb{Z}[x]$
51695
Finding all homomorphisms between $\mathbb{Z}/m\mathbb{Z}$ and $\mathbb{Z}/n\mathbb{Z}$
135241
Show that $\mathbb{Z}/n^2\mathbb{Z}$ is not isomorphic to other group