A centrally essential ring is a ring with a nonzero multiplicative
identity such that, for every nonzero
, there are nonzero elements
in the ring center with
.
Thus multiplying
by a suitable nonzero central element produces a nonzero central
element (Markov and Tuganbaev 2018). Every commutative
ring with a nonzero multiplicative identity
is centrally essential, but the converse fails.
Abyzov et al. (2026) proved that the smallest finite ring that is centrally essential and noncommutative has 64 elements. They also exhibited nonisomorphic examples of this smallest order.