Not even close to 2B users. Google have probably 10 different products with more than 2B monthly users.
It's very hard to believe. Besides search, Android, Chrome and Gmail are in 2B~4B range. Are there really another 6 products that are ubiquitous as these 3? Google Docs definitely doesn't have 2B monthly users. Some built-in Android apps might be installed on >2B phones, but it doesn't mean they have that many active users.
The article mentions they have six products with 2 billion users.
Google Search,
Android,
Chrome,
Gmail,
Google Play Store, and
YouTube
Also Google Maps, Google Photos and Google Drive have more than 1B users.