Show the $(p-1)! \equiv -1 \mod p/$...
2218
Prove that $(n-1)! \equiv -1 \pmod{n}$ iff $n$ is prime [Wilson's Theorem]
138941
If p $\equiv$ 3 (mod 4) with p prime, prove -1 is a non-quadratic residue modulo p.
43567
Some hints for "If a prime $p = n^2+5$, then $p\equiv 1\mod 10$ or $p\equiv 9\mod 10$"
75528
$x^2-x+1$ has a root $\!\bmod p\,$ for infinitely many primes $p$
45171
How prove this $(p-1)!\left(1+\frac{1}{2}+\frac{1}{3}+\cdots+\frac{1}{p-1}\right)\equiv 0\pmod{p^2}$
127816
Number theory proof mod p
66861
Show that $11^{10} \equiv 1 (\mod 100)$
94917
Prove that for every prime $p$, there exists a solution to $(x^2-2)(x^2-6)(x^2-3) \equiv 0 \mod(p)$
158863
How to prove $\sum_p p^{-2} < \frac{1}{2}$?
15314
Number of solutions to $x^n \equiv 1 \mod p$
145884
Showing $\left|\frac{a+b}{2}\right|^p+\left|\frac{a-b}{2}\right|^p\leq\frac{1}{2}|a|^p+\frac{1}{2}|b|^p$
134450
Chinese Remainder Theorem $\ x\equiv m_k-2\pmod{m_k}$
134348
When is $(p - 1)! + 1$ a power of $p$?
9920
$(n^2 - 1)!$ is a multiple of $(n!)^n$
60305
Proving the congruence $p^{q-1}+q^{p-1} \equiv 1 \pmod{pq}$
74512
How to show $n(n+1)(2n+1) \equiv 0 \pmod 6$?
5206
Highest power of a prime $p$ dividing $N!$