Are all congruence relations on $(\mathbb{Z},+)$ of the form mod n for some integer n?
119360
Find all subrings of $\mathbb{Z}^2$
19071
solution set for congruence $x^2 \equiv 1 \mod m$
4972
Mod of numbers with large exponents [modular order reduction]
139934
In $\mathbb{Z}/(n)$, does $(a) = (b)$ imply that $a$ and $b$ are associates?
11935
Is $\mathbb{Z} \left[ \frac{1+i \sqrt{7}}{2} \right]$ euclidean?
127945
Number of solutions to the congruence $x^q \equiv 1 \mod p$.
139
Prove or disprove: For every integer a, if a is not congruent to 0 (mod 3), the a^2 is congruent to 1 (mod 3)
11500
Divisibility by 7 rule, and Congruence Arithmetic Laws
74898
$1^n +2^n + \cdots +(p-1)^n \mod p =$?
18245
How to check if a system of congruence is solvable?
11342
Show that conguence $\bmod m\,$ is an equivalence relation
85449
Show a,b,c congruences when $a^2+b^2=c^2$
105225
Number Theory: Complete set of residues modulo $n$
5223
$\mathbb{Z}_m \times \mathbb Z_n$ is cyclic if and only if $\gcd(m,n)=1$
65218
Let $m \in \mathbb{Z^+} , n \in \mathbb{Z^+}$ and let $d=\gcd(m,n)$. Prove that $m\mathbb{Z}+n\mathbb{Z}=d\mathbb{Z}$
98731
Show that there is no epimorphism from ($\mathbb{Q}$, +) to ($\mathbb{Z}$, +)
9129
Show that $\mathbb{Q}(\zeta_n)$ is Galois over $\mathbb{Q}$ and $Gal(\mathbb{Q}(\zeta_n)/\mathbb{Q}))\cong \mathbb{Z_n}^*$