changelessness vs unchangeability

changelessness and unchangeability both are nouns.

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

As nouns, changelessness and unchangeability are synonyms defined as:

changelessness and unchangeability: the quality of being unchangeable; having a marked tendency to remain unchanged

Other synonyms of changelessness include unchangeableness, unchangingness.

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