currently, orthodox QM does not assign any frequency as being a characteristics of an electron (as charge, spin, magnetic moment) however there are models or theories of electron that gives this attribute to the electron. In RG (i.e here) you can find article "The nature of the electron by Qui-hong Hu from Gothenburg University." You can, as well, look to the Hestenes model of electron or to go back in time to de Broglie and Schrodinger who were confident with at least one frequency being a real property of electron at rest, equal to mc^2/h. I myself have found two frequencies that can be attributed as internal property of electron, one increasing with increasing energy of en electron and one decreasing according to Lorentz transformation.