The word "atypicalness" means something that deviates from the usual or typical. Its antonyms are "normalcy," "typicality," and "conformity." These words denote a state of being normal or conforming to the standard, expected way of doing things. "Normalcy" refers to a state of being normal or usual, while "typicality" describes something characterized by the usual or standard. "Conformity" means acquiescence or compliance with the norms, standards, or expectations of a group or society. Using antonyms like "normalcy," "typicality," and "conformity" can help express the opposite meaning of atypicalness in various contexts.