She is among the most creative of the artists around today.

[WilliamTaft]

With the meaning of "existing," The Britannica Dictionary says "around" is a adjective, but the Longman Contemporary says it's a adverb.

One of Britannica's examples: She is among the most creative of the artists around today.
One of Longman's examples: That joke’s been around for years.

Are both of them acceptable?

 

[Annabel Lee]

In each case, “around” may be categorized as a preposition—an intransitive preposition, i.e. one used without an object. Prepositions can function both adjectivally and adverbially.

 

[emsr2d2]

an adjective
an adverb