2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/224327The purpose of this paper is to define the r-th Tachibana number t(r) of an n-dimentional closed and oriented Riemannian manifold (M,g) as the dimension of the space of all conformal Killing r-forms for r=1,2,...,n-1 and to formulate some properties of these numbers as an analogue to properties of the r-th Betty number b(r) of a closed and oriented Riemannian manifold.Differential Geometry58A10; 58G25text