It acts like Arrhenius base.
The Arrhenius acid-base concept classifies a substance as an acid if it produces hydrogen ions H(+). A substance is classified as a base if it produces hydroxide ions OH(-) in water. Other ways of classifying substances as acids or bases are the Bronsted-Lowry concept and the Lewis concept.
But when you look Na(+) or OH(-) seperetly then you have to consider other theories as well.