Is there any general solution technique for $\phi(n)=m$ where $m\in\mathbb{N}$ is given?
9753
How to solve the equation $\phi(n) = k$?
155266
Is $\exp:\overline{\mathbb{M}}_n\to\mathbb{M}_n$ injective?
106401
Prove: $p-mq | f(m)$ where $m$ is any integer
880
Find all n such that $\phi(n) = n/2$
96095
If $\{a_1,\dots,a_{\phi(n)}\}$ is a reduced residue system, what is $a_1\cdots a_{\phi(n)}$ congruent to?
61858
Is there $\phi(n)=n/6$
53263
Show $\sum\limits_{d|n}\phi(d) = n$.
35664
If $x^m=e$ has at most $m$ solutions for any $m\in \mathbb{N}$, then $G$ is cyclic
97258
Give $\ker(\phi)$ for $\phi: \mathbb{Z} \to \mathbb{Z_7}$ such that $\phi(1)=4$
151354
Why are there no non-trivial regular maps $\mathbb{P}^n \to \mathbb{P}^m$ when $n > m$?
145835
Closed form for CRT solution using Euler $\phi\,$ (totient)
82878
Order of cyclic groups and the Euler phi function
52951
Find all $n \in \mathbb{Z^+}$ such that $\phi(n)=4$
135219
On the mean value of a multiplicative function: Prove that $\sum\limits_{n\leq x} \frac{n}{\phi(n)} =O(x) $
63769
Group theory proof of Euler's theorem ($a^{\phi(m)} \equiv 1\mbox{ }(\mbox{mod }m)$ if $\gcd(a,m)=1$)
157213
Application of Luca's theorem
136623
Hints/ Solution in finding a formula $\phi(n)$ for a binary square matrix