Necessity of coprimeness in Carmichael numbers
42780
Show that if $a^{n-1} \equiv 1 \pmod{n}$ for all $a$ such that $\gcd(n,a) = 1$, then $a^{n} \equiv a \pmod{n}$ for all $a$.
74615
Carmichael number square free
54358
Why $(1-\zeta)$ unit where $\zeta$ is a primitive nth and n divisible by two primes
54430
For $a,b$ coprime, there exists positive integers $x,y$ such that $ax-by=1$
19164
On the GCD of a Pair of Fermat Numbers
105225
Number Theory: Complete set of residues modulo $n$
50249
Pairs of numbers with a given LCM
82878
Order of cyclic groups and the Euler phi function
14783
A Number Theory problem (GCD)
74924
identity element of $(D_n ,\gcd)$
147197
Number of connected components of the complement of a compact
156910
Necessary and sufficient condition for $R/IJ \cong R/I \times R/J$
151520
About the parity of the product $(a_1-1)(a_2-2)\cdots(a_n-n)$
135682
Are distinct prime ideals in a ring always coprime? If not, then when are they?
1713
number theory $\gcd(a,bc)=\gcd(a,c)$
114916
$\mathbb Z_{mn}$ isomorphic to $\mathbb Z_m\times\mathbb Z_n$ whenever $m$ and $n$ are coprime
130162
A complete residue system from an arithmetic progression