I have an app on the Play Store. I recently completed 500 downloads of the app. The Google Play Developer Console is showing 525 installs as of 2 days ago (29th May):
So, the data is already 2 days old. But on the play store, it still shows
Play Developer Console
The count of installs on your app page is rounded up (or for better understanding milestone based). As and when you reach thresholds the displayed count changes.
You have crossed 500 now so it shows 500. Your next milestone is 1000. Once you cross 1000 downloads the number on your app page on play store will show
1000 downloads. There after 5k, 10k, 50k, 100k, 500k, 1M and so on.
Also the updates take time and are not instantaneous. It may sometimes take over a week and sometimes just a day. Depends on when google's data processing jobs to update the statistics executes.