imaginary vs imaginary number

imaginary and imaginary number both are nouns.

Word	Noun	Adjective	Verb	Adverb
imaginary	Yes	Yes	No	No
imaginary number	Yes	No	No	No

As nouns, imaginary and imaginary number are synonyms defined as:

imaginary and imaginary number: (mathematics) a number of the form a+bi where a and b are real numbers and i is the square root of -1

Other synonyms of imaginary include complex number, complex quantity.

imaginary (noun)	imaginary number (noun)
(mathematics) a number of the form a+bi where a and b are real numbers and i is the square root of -1	(mathematics) a number of the form a+bi where a and b are real numbers and i is the square root of -1

imaginary (adjective)	imaginary number (adjective)
not based on fact; existing only in the imagination