GaussianIntegers
is an option for FactorInteger, PrimeQ, Factor, and related functions that specifies whether factorization should be done over Gaussian integers.
Details

- With GaussianIntegers->False, factorization is done over the ordinary ring of integers
.
- With GaussianIntegers->True, factorization is done over the ring of integers with i adjoined
.
- The Gaussian primes used when GaussianIntegers->True are chosen to have both real and imaginary parts positive.
- The first entry in the list given by FactorInteger with GaussianIntegers->True may be -1 or -I.
Examples
open allclose allBasic Examples (1)Summary of the most common use cases
Scope (3)Survey of the scope of standard use cases
By default polynomial factorization is performed over the rationals:

https://wolfram.com/xid/0ywh8bcjdf3c-4ql3h

This specifies that the factorization should be done over :

https://wolfram.com/xid/0ywh8bcjdf3c-ffoavo

By default integer factorization is performed over the integers:

https://wolfram.com/xid/0ywh8bcjdf3c-ic6qe2

This specifies that the factorization should be done over the Gaussian integers:

https://wolfram.com/xid/0ywh8bcjdf3c-l50iga

A number prime over the integers may not be prime over the Gaussian integers:

https://wolfram.com/xid/0ywh8bcjdf3c-jqwj4k


https://wolfram.com/xid/0ywh8bcjdf3c-krrkvs

Properties & Relations (1)Properties of the function, and connections to other functions
For Factor, GaussianIntegers->True is equivalent to Extension->I:

https://wolfram.com/xid/0ywh8bcjdf3c-btgb1f


https://wolfram.com/xid/0ywh8bcjdf3c-bs2ioe

Wolfram Research (1991), GaussianIntegers, Wolfram Language function, https://reference.wolfram.com/language/ref/GaussianIntegers.html.
Text
Wolfram Research (1991), GaussianIntegers, Wolfram Language function, https://reference.wolfram.com/language/ref/GaussianIntegers.html.
Wolfram Research (1991), GaussianIntegers, Wolfram Language function, https://reference.wolfram.com/language/ref/GaussianIntegers.html.
CMS
Wolfram Language. 1991. "GaussianIntegers." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/GaussianIntegers.html.
Wolfram Language. 1991. "GaussianIntegers." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/GaussianIntegers.html.
APA
Wolfram Language. (1991). GaussianIntegers. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/GaussianIntegers.html
Wolfram Language. (1991). GaussianIntegers. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/GaussianIntegers.html
BibTeX
@misc{reference.wolfram_2025_gaussianintegers, author="Wolfram Research", title="{GaussianIntegers}", year="1991", howpublished="\url{https://reference.wolfram.com/language/ref/GaussianIntegers.html}", note=[Accessed: 06-April-2025
]}
BibLaTeX
@online{reference.wolfram_2025_gaussianintegers, organization={Wolfram Research}, title={GaussianIntegers}, year={1991}, url={https://reference.wolfram.com/language/ref/GaussianIntegers.html}, note=[Accessed: 06-April-2025
]}