An irreducible algebraic integer which has the property that, if it divides the product of two algebraic integers,
then it divides at least one of the factors. 1 and 
are the only integers
which divide every integer.
They are therefore called the prime units.
Prime Algebraic Number
See also
Algebraic Integer, Prime UnitExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Prime Algebraic Number." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/PrimeAlgebraicNumber.html