Euler's totient function determining $\phi(m)$= 2 using the product formula.
52951
Find all $n \in \mathbb{Z^+}$ such that $\phi(n)=4$
154841
Computing symmetry/combinatorial factor for a diagram in $\phi^4$ theory
104828
Show that $\cot \frac{\pi}{2m}\cot \frac{2\pi}{2m}\cot \frac{3\pi}{2m}...\cot \frac{(m-1)\pi}{2m}=1$
1970
Inverse Euler totient function
124220
Using Euler's Totient Function, how do I find all values n such that $\phi(n)=12$?
158515
Identity involving Euler's totient function: $\sum \limits_{k=1}^n \left\lfloor \frac{n}{k} \right\rfloor \varphi(k) = \frac{n(n+1)}{2}$
126574
Proving $\prod_k \sin \pi k / n = n / 2^{n-1}$
55984
How can I find the answer to $\varphi(2^{400} + 2)$?
37346
If $m, n$ be positive integers, prove that $\phi(mn)=\phi((m,n))\phi([m,n])$, where $(m,n)=$ gcd of $m, n$ and $[m, n]=$ lcm of $m, n$.
147111
Where is the Proof for the Sum-to-Product rule derrived from?
80670
'Lines' in the Euler phi graph
49938
Proof of $a^{\phi (n) +1} \equiv a \pmod{\! n} $ Carmichael generalization of Fermat-Euler's theorem.
132587
Prove that the product of coprimes must be congruent to $-1$ or $1 \pmod{m}$
137982
Show that $\textbf{ZF}$ shows $\phi$ is $\Delta_1$
138819
Prove that $\phi(n) \geq \sqrt{n}/2$
75279
Reversing the $T(n) = \frac{n(n+1)}{2}$ formula
66061
Why is the formula for calculating euler totient true?