Characteristic

Pub Apr 06, 2026 Up Jun 11, 2026

Definition 1. Let $R$ be a ring. The characteristic of $R$, denoted by

\[\chara R,\]

is the smallest $n \in \N^+$ such that

\[n \cdot 1 = 0,\]

if it exists. Otherwise, we let $\chara R = 0$.