SEGA Atlus’s revered Persona series of video games have now shifted over 23.5 million copies worldwide, which is a phenomenal achievement for the JRPG series. In the company’s recent financial report, SEGA attributes the fast sales growth for both the Persona and Like a Dragon franchises to simultaneous worldwide releases on multiple platforms, well as remaster and spin-off titles. The Persona 5 series alone has shifted sold over 10 million copies worldwide.
Persona series sells over 23.5 million copies worldwide

Common Persona W
I think you meant the Persona 5 series has sold over 10 million, not Persona 4.