A multiplicative property of the Euler totient function $\phi$
53426
Proof of a formula involving Euler's totient function: $\varphi (mn) = \varphi (m) \varphi (n) \cdot \frac{d}{\varphi (d)}$
9612
Frattini subgroup $Φ ( G )$ is not trivial
46147
Proving $(\forall a\in\mathbb{Z^+})(m\in\mathbb{Z^+}\to a^m\equiv a^{m-\phi(m)}\pmod{m})$
8784
modulo version of the quadratic formula and Euler's criterion
8311
Is there another proof for Euler–Mascheroni Constant?
88598
Property of $\{0^n, 1^n, \ldots\}$
157711
Number Theory: Prove that $m | \phi(a^m - 1)$
82448
Why is $f(x) = x\phi(x)$ one-to-one?
34960
Lower bound for $\phi(n)$: Is $n/5  1$?
12976
Prove $\displaystyle\lim_{n\to\infty}\phi(n)=\infty$.
17178
Order of $\phi(g)$ divides the order of $g$
82878
Order of cyclic groups and the Euler phi function
122519
Multiplicative Functions
78342
When is $\phi(n)$ a prime number?
44496
Norm $N$ on $\Bbb Z[\sqrt d]$ is multiplicative, $N(x)$ prime $\Rightarrow x$ irreducible
1970
Inverse Euler totient function
46065
How do you find all $n$ such that $\phi(n)|n$