Suppose that $n$ is a factor of $(n-1)!+1$. Prove that $n$ is prime
2218
Prove that $(n-1)! \equiv -1 \pmod{n}$ iff $n$ is prime [Wilson's Theorem]
34738
Prove that $\gcd(n!+1,(n+1)!+1)=1$
75685
Prove that there is prime number and natural so $n\times q$ digits are $1$.
34588
Number Theory: $p!+p=n^2$, $p$ = prime
51382
Proving that either $2^n-1 $ or $ 2^n+1$ is not prime
130842
Prime factors + number of Divisors
86413
Show that $\frac{(m+n-1)!}{m!n!}$ is an integer where m and n are positive integers and gcd(m,n)=1
10742
Powers of prime factors of a positive integer $n$ in "Mathematica"?
60804
About the property of $m$: if $n < m$ is co-prime to $m$, then $n$ is prime
131385
How to provide a counterexample for if $n$ is prime, then $2^n -1$ is prime
79208
Is the number $-1$ prime?
116361
Relationship between prime factorizations of $n$ and $n+1$?
26514
Prove that if $n$ is a composite, then $2^n-1$ is composite.
66851
If $p,q$ are primes $(pq,a)=1$ and $p-1|q-1$ then prove $a^{q-1}\equiv 1\pmod{pq}$
15348
prime divisor of $3n+2$ proof
144575
Factoring n, where n=pq and p and q are consecutive primes
78342
When is $\phi(n)$ a prime number?