Are there any positive integers n for which $\phi(n) = \frac{n}{4}$?
60284
Infinitely many positive integers $n$ such that $\phi(n) = \frac{n}{4}$?
45939
For which $n≥2$ does there exist $\sigma\in A_n$ with $|\sigma| > n$
26233
$[K(\zeta_n):K]=\phi(n)$?
51445
Number Theory: Find all solutions of $\phi(n)=16$ and $\phi(n)=24$
46741
Prove that $n$ divides $\phi(a^n -1)$ where $a, n$ are positive integer without using concepts of abstract algebra
50927
If $m,n\in N$ Prove that there is such a positive integer k, such that $(\sqrt{m}+\sqrt{m+1})^n=\sqrt{k}+\sqrt{k+1}$
96095
If $\{a_1,\dots,a_{\phi(n)}\}$ is a reduced residue system, what is $a_1\cdots a_{\phi(n)}$ congruent to?
9753
How to solve the equation $\phi(n) = k$?
126656
Convergence or divergence of $\sum\limits_n(-1)^{\pi(n)}\frac1n$ where $\pi(n)$ is the number of primes less than or equal to $n$
34960
Lower bound for $\phi(n)$: Is $n/5  1$?
91889
Prove $\phi^n = \phi F_n + \text{(another Fibonacci number)}$ using mathematical induction.
4512
Is there a direct, elementary proof of $n = \sum_{k|n} \phi(k)$?
17178
Order of $\phi(g)$ divides the order of $g$
100515
Prove that if $d$ divides $n$ then $φ(d)$ divide $φ(n)$ for $φ$ denotes Euler’s φ-function.
91451
find all positive integer $m,n$
61858
Is there $\phi(n)=n/6$
46147
Proving $(\forall a\in\mathbb{Z^+})(m\in\mathbb{Z^+}\to a^m\equiv a^{m-\phi(m)}\pmod{m})$