invariability vs changelessness

invariability and changelessness both are nouns.

Word	Noun	Adjective	Verb	Adverb
invariability	Yes	No	No	No
changelessness	Yes	No	No	No

As nouns, changelessness is a hypernym of invariability; that is, changelessness is a word with a broader meaning than invariability:

invariability: the quality of being resistant to variation
changelessness: the quality of being unchangeable; having a marked tendency to remain unchanged

Other hypernyms of invariability include unchangeability, unchangeableness, unchangingness.

invariability (noun)	changelessness (noun)
the quality of being resistant to variation	the quality of being unchangeable; having a marked tendency to remain unchanged
a quality of uniformity and lack of variation	the property of remaining unchanged