Does $(p-n)!$ congruence modulo p
7932
$(p\!-\!1\!-\!h)!\,h! \equiv (-1)^{h+1}\!\!\pmod{\! p}\,$ [Wilson Reflection Formula]
52542
For which odd positive integer $n$ , is it true that $-1$ is not a positive power of $2$ modulo $n$?
107990
Does there exist an integer $x$ satisfying the following congruences?
41673
Solve congruence system $\ x\equiv m_i-1 \pmod{m_i}\,$ for $\,i = 1,\ldots, k$
45882
Solving a congruence without Fermat's little theorem
71788
Prove existence of multiplicative inverse modulo p when p is prime
61825
Congruence class $[a]$ modulo $m$, $\gcd(x, m) = \gcd(a, m)$
38727
Modular Exponentiation and Primes
14724
For primes $p≡3\pmod 4$, prove that $[(p−1)/2]!≡±1\pmod p$.
32762
Proof for: $(a+b)^{p} \equiv a^p + b^p \pmod p$
52530
There exists a prime congruent to $m$ mod $p$
27287
$-1$ is a quadratic residue modulo $p$ if and only if $p\equiv 1\pmod{4}$
127816
Number theory proof mod p
122741
$x^2$ is congruent to $-1 \bmod p$
94917
Prove that for every prime $p$, there exists a solution to $(x^2-2)(x^2-6)(x^2-3) \equiv 0 \mod(p)$
93820
Fermat's little theorem applied for $n$'th root existence $\!\bmod p$
134348
When is $(p - 1)! + 1$ a power of $p$?