If you were looking for a review of a specific or ARG (Alternate Reality Game) that uses this type of cryptic naming, there are currently no major documented entries under this exact numerical string.
: Represents the date the file was created (September 21, 2021). 04 20210921074351 mp4
: The standard digital multimedia container format used for video and audio. How to Review or Open the File If you were looking for a review of
: Represents the exact time of recording (07:43:51 AM). 04 20210921074351 mp4
Are you trying to with this name, or did you find this string in a specific forum or game? What is MP4 Format Video?