Property of modular arithmetic.
55049
How to find the inverse modulo $m$?
94855
Prove if a (mod n) has a multiplicative inverse, then it's unique
42754
Modular arithmetic: division, fractions, solving linear congruences
90537
Converse of Fermat's Little Theorem.
141369
If $a+b\equiv0\pmod m$ and $c+d\equiv 0\pmod m$ then $ac\equiv bd\pmod m$. Demonstration.
12210
Show that $a^{61} \equiv a\pmod{1001}$ for every $a \in \mathbb{N}$
134450
Chinese Remainder Theorem $\ x\equiv m_k-2\pmod{m_k}$
59566
Proving that $ka \equiv kb \pmod{m} \iff a \equiv b \pmod{m/\gcd(k,m)}$
101057
Show that $1^{p-1} + 2^{p-1} +\ldots + (p-1)^{p-1} \equiv -1 \mod p$
71788
Prove existence of multiplicative inverse modulo p when p is prime
14809
Existence & uniqueness of solutions of linear congruences $\ cx\equiv b\pmod m$
45460
Proof verification of a number theory problem involving sequences.
22029
Solving modular arithmetic questions
22053
Modular Arithmetic - Pirate Problem
81687
What is the importance of Modular arithmetic in cryptography?
39969
Algorithms for computing multiplicative order modulo $n$
49294
prove that $\operatorname{lcm}(n,m) = nm/\gcd(n,m)$