Greatest common divisor and relative primes
5789
$ d = \gcd(a,b)\Rightarrow\ \gcd(a/d,b/d) = 1$
63865
Fermat primality test $\gcd$ condition and carmichael numbers
75516
Relatively Prime Numbers and Number of Divisors of n
124279
$g^k$ is a primitive element modulo $m$ iff $\gcd (k,\varphi(m))=1$
12862
Prove that two distinct numbers of the form $a^{2^{n}} + 1$ and $a^{2^{m}} + 1$ are relatively prime if $a$ is even and have $\gcd=2$ if $a$ is odd
41295
Divisibility, LCM and GCD for fractions (rationals)
119734
Why does prime factorization for LCM work?
41926
Why do we say "lowest common denominator" when we mean "greatest common divisor"?
74314
Noetherian ring and the same prime divisors
130615
divisibility of binomial coefficients by primes
116361
Relationship between prime factorizations of $n$ and $n+1$?
14693
$d = \gcd(c,m),\ ac≡bc\pmod{\! m}\Rightarrow a≡b\pmod {\!m/d}\ $ [Congruence Cancellation & Division Rule]
62959
How to find GCD, LCM on a set of numbers
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 $5$
14783
A Number Theory problem (GCD)
102979
If $[G:H]$ and $[G:K]$ are relatively prime, then $G=HK$
10966
gcd and lcm from prime factorization proof