Zero-Divisors & Units in $\mathbb{Z}/n\mathbb{Z}$
14343
Every nonzero element in a finite ring is either a unit or a zero divisor
119052
Finding invertible elements in $\mathbb{Z}/m\mathbb{Z}$
16507
Is $\mathbb{Z}= \{\dots -3, -2, -1, 0 ,1 ,2 , 3, \dots \}$ countable?
121663
If $a$ is a zero divisor of $\mathbb{F}$, then does $a$ fail to have a multiplicative inverse?
29452
Divisor in $\mathbb{C}[X]$ $\implies$ divisor in $\mathbb{R}[X]$?
137422
$\mathrm{card}(\mathbb{Z}^n/M\mathbb{Z}^n) = |\det(M)|$?
74441
Zero divisors in matrix rings
133019
Nilpotent elements in $\mathbb Z_n$
122312
How can I compute $\mathrm{Aut}(\mathbb{Z}/4\mathbb{Z}\times\mathbb{Z}/6\mathbb{Z})$?
52966
Rings, ideals and units-proof
95863
Describe the units in $\mathbb{Z}[\sqrt{-d}]$
146304
prove $(n)$ prime ideal of $\mathbb{Z}$ iff $n$ is prime or zero
118299
Show that $(\mathbb{Z}[x]/(x^{n+1}))^{\times}\cong \mathbb{Z}/2\mathbb{Z}\times\Pi_{i=1}^n\mathbb{Z}$
20613
Units (invertibles) of polynomial rings over a field
8434
Order of $\mathbb{Z}[i]/(1+i)$
114254
Zero divisors in $A[x_1,x_2,\dots,x_r]$
59134
Proving idempotent elements in $\mathbb{Z}_n$