We show that a finite dimensional algebra A has dominant dimension at least n ≥ 2 if and only if the regular bimodule A is n-torsionfree if and only if A ∼ = Ω n (Tr(Ω n−2 (V ))) as A-bimodules, where V = Hom A (D(A), A) is the canonical A-bimodule in the sense of [FKY]. We apply this to give new formulas for the Hochschild homology and cohomology for algebras with dominant dimension at least two and show a new relation between the first Tachikawa conjecture, the Nakayama conjecture and Gorenstein homological algebra.