The string of numbers is a in milliseconds, which represents the exact moment the file was created or saved. Timestamp: 1565839234123 Date: Thursday, August 15, 2019 Time: Approximately 03:20:34 AM (UTC)
This naming convention is frequently used by platforms that need to give files unique names instantly without user input: 1565839234123 mp4
If you "Save Video As" from certain web players, they default to the server's unique identifier for that asset. How to View the Content The string of numbers is a in milliseconds,
VLC Media Player is highly recommended as it can play almost any .mp4 variant even if the file is slightly corrupted. 1565839234123 mp4