Unit divisor

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2020 Mathematics Subject Classification: Primary: 15-XX Secondary: 13A05 [MSN][ZBL]

An element $a$ of a ring (with a unit element 1) for which there exists an inverse, i.e. an element $b$ such that $ab=ba=1$. In the theory of algebraic numbers and algebraic functions such elements are also called units.


The phrases divisor of unity or invertible element are also used for this notion.

See Divisibility in rings for the general theory.

How to Cite This Entry:
Unit divisor. Encyclopedia of Mathematics. URL:
This article was adapted from an original article by O.A. Ivanov (originator), which appeared in Encyclopedia of Mathematics - ISBN 1402006098. See original article