Android is a ludicrously popular operating system, and Google let us know just how popular at its I/O keynote today. According to Android director Stephanie Cuthbertson, there are more than two and a half billion active Android devices around the world today.
— Android (@Android) May 7, 2019
Those 2.5 billion devices were produced by more than 180 hardware manufacturers, and they're not all smartphones. The number also encompasses just about any device with Google Assistant built in, including smart speakers, smart displays, and even KaiOS phones.
Google has finally published updated Android distribution numbers for the first time since last October; you can check those out here.