mid-twenties vs twenties

mid-twenties and twenties both are nouns.

Word	Noun	Adjective	Verb	Adverb
mid-twenties	Yes	No	No	No
twenties	Yes	No	No	No

As nouns, mid-twenties and twenties are synonyms defined as:

mid-twenties (noun)	twenties (noun)
the time of life between 20 and 30	the time of life between 20 and 30
	the decade from 1920 to 1929