I got interested myself and did a quick search, but it doesn’t seem like Riot have live stats unfortunately. I would expect League of Legends to have more players, but I don’t think it would be that huge, especially considering how popular Dota is in non-western countries.

I also find it funny how if you search something like “dota vs lol player count”, most of the spammy sites just compare the number you gave or even worse comparing Dota’s 1m peak concurrent per month vs League’s 150m total a month.

There also seems to be a disparity in the number of accounts that most players have per game (smurfs) making this probably not worth the time to research!