TONER FOR DEVELOPING ELECTROSTATIC CHARGE IMAGE, ELECTROSTATIC CHARGE IMAGE DEVELOPER, TONER CARTRIDGE, PROCESS CARTRIDGE, AND IMAGE FORMING APPARATUS

A toner for developing an electrostatic charge image includes toner particles having an average circularity Cc of 0.80 or more and less than 0.98, and an external additive containing monodisperse silica particles and titanate compound particles, in which a ratio Rt/Rs of an average primary particle diameter Rt of the titanate compound particles to an average primary particle diameter Rs of the monodisperse silica particles is 0.50 or more and 3.50 or less, and a ratio A/B of an external additive coverage A (%) of the monodisperse silica particles on surfaces of the toner particles to an external additive coverage B (%) of the titanate compound particles on the surfaces of the toner particles satisfies formula (1): 0