immutability vs changelessness

immutability and changelessness both are nouns.

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

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

immutability: the quality of being incapable of mutation
changelessness: the quality of being unchangeable; having a marked tendency to remain unchanged

Other hypernyms of immutability include unchangeability, unchangeableness, unchangingness.

immutability (noun)	changelessness (noun)
the quality of being incapable of mutation	the quality of being unchangeable; having a marked tendency to remain unchanged
	the property of remaining unchanged