This specific numeric string (starting with 5_ ) is a signature of files cached or downloaded from Telegram .
Investigators often find these files in the Telegram Desktop or Telegram Video cache folders during data recovery. 5_6208618519085450864.mp4
The long string of digits serves as a unique ID within the platform's database to ensure no two files conflict, even if they originally had the same name (like "video.mp4"). This specific numeric string (starting with 5_ )
In professional and investigative circles, files with these names are often encountered in: 5_6208618519085450864.mp4
If you received this file in a group chat or via a file-sharing service, the name was likely preserved from the sender's local Telegram cache.