prime and irreducible elements $\equiv 1$ modulo $4$
124926
Are Hilbert primes also Hilbert irreducible ? Furthermore, are Hilbert primes also primes in $\mathbb{ Z}$?
9787
Primitive roots modulo primes congruent to n!
105442
Show that any prime divisor of $x^4+x^3+x^2+x+1$, with $x\in\mathbb{N}$, is $5$ or $1$ mod $5$
153862
A question about a primitive root mod $p=2^{2^k}+1$, where $p$ is prime.
50412
Prime elements in $\mathbb{Z}/n\mathbb{Z}$
101057
Show that $1^{p-1} + 2^{p-1} +\ldots + (p-1)^{p-1} \equiv -1 \mod p$
34323
Prove that $a^{(p-1)/2} \equiv 1$ (mod p) and $a^{(p-1)/2} \equiv -1 \pmod p$
124279
$g^k$ is a primitive element modulo $m$ iff $\gcd (k,\varphi(m))=1$
100255
If a prime divides the hypotenuse of a primitive Pythagorean triple, then $p \equiv 1$ (mod 4)
107381
Understanding the proof of infinitely many primes $\equiv 3\pmod{\!4}$
65558
Irreducible in $\mathbb{Z}[\sqrt{-5}]$
23153
$\bmod p\!:\ x^2\equiv 1\iff x\equiv \pm1\ $ for prime $p$
52530
There exists a prime congruent to $m$ mod $p$
97902
In a integral domain every prime element is irreducible
127901
If $x^2+y^2 \equiv 0\pmod{p}$, then $p \equiv 1 \pmod{4}$
75318
How do you prove that a prime is the sum of two squares iff it is congruent to 1 mod 4?
16592
Irreducible polynomial which is reducible modulo every prime