Basically twice the numbers of League of Legends.
Wouldn't say that. The last time the total registered players was revealed for League of Legends was 2012, when they had 32m Monthly Active Players and 70m Total Players.
Back in 2016 they said League was now getting 100m players each month so I wouldn't be surprised if Lol was now higher than 200m registered players.
To be fair, I believe (can't stress this enough) League has been on a decline in the last two years. Nothing massive, they still get a ton of viewers for their finals but generally speaking, the internet seemed to agree that numbers were slowing down. I don't think Riot has released these sort of information in the past 2 years or so, or at least they aren't as public about it. I read your response to somebody else, thought it was active users, disregard all of this.
OT: I will never understand how this got so popular, looks even more repetitive than MOBAs (and I love league). Seems like Epic games is being pretty kind and helpful to the community and they aren't being scummy.