Atlus has announced that Shin Megami Tensei IV, released in Japan in May 2013 and NA in July 2013, has sold over 600k copies worldwide.
I believe the latest number we have for the sales only in Japan is this:
Also, there's gonna be an "Atlus Best Collection" of SMT IV in Japan on October 8, 2015, for 2,980 yen.
— Twitter
I believe the latest number we have for the sales only in Japan is this:
So around 262k copies in Japan. I haven't looked into WW numbers for previous SMT mainline games, but this seems pretty good. Possibly the most successful SMT game yet.[3DS] Shin Megami Tensei IV # <RPG> (Atlus) {2013.05.23} (¥6.980) - 4.250 / 262.150 (188.562 <80,14%>)
Also, there's gonna be an "Atlus Best Collection" of SMT IV in Japan on October 8, 2015, for 2,980 yen.
— Twitter