one vs 1

one and 1 both are nouns.

Word	Noun	Adjective	Verb	Adverb
one	Yes	Yes	No	No
1	Yes	Yes	No	No

As adjectives, one and 1 are synonyms defined as:

Other synonyms of one include ane, i.

As nouns, one and 1 are synonyms defined as:

Other synonyms of one include ace, I, single, unity.

one (noun)	1 (noun)
a single person or thing	the smallest whole number or a numeral representing this number
the smallest whole number or a numeral representing this number

one (adjective)	1 (adjective)
used of a single unit or thing; not two or more	used of a single unit or thing; not two or more
being a single entity made by combining separate components
(informal) very; used informally as an intensifier
eminent beyond or above comparison
indefinite in time or position
of the same kind or quality
having the indivisible character of a unit