Product of the Euler phi function
53426
Proof of a formula involving Euler's totient function: $\varphi (mn) = \varphi (m) \varphi (n) \cdot \frac{d}{\varphi (d)}$
136623
Hints/ Solution in finding a formula $\phi(n)$ for a binary square matrix
49044
Question about Eulers formula $v - e + f = 2$
51679
Simplifying the product $\prod\limits_{k=2}^n \left(1-\frac1{k^2}\right)$
94558
Show that $\phi(mn) = \phi(m)\phi(n)\frac{d}{\phi(d)}$
140249
Euler Product formula for Riemann zeta function proof
100515
Prove that if $d$ divides $n$ then $φ(d)$ divide $φ(n)$ for $φ$ denotes Euler’s φ-function.
157711
Number Theory: Prove that $m | \phi(a^m - 1)$
119118
Prove $n\mid \phi(2^n-1)$
149589
Analogous results to Euler's theorem
1970
Inverse Euler totient function
97192
product of harmonic functions
125876
Sum and Product of Infinite Radicals
72904
Evaluation of $\prod_{n=1}^\infty e\left(\frac{n}{n+1}\right)^{n}\sqrt{\frac{n}{n+1}}$
137380
Euler's Constant: The asymptotic behavior of $\left(\sum\limits_{j=1}^{N} \frac{1}{j}\right) - \log(N)$
17690
Ways to prove Euler's formula for $\zeta(2n)$
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 $m, n$.