The filename is a generic numeric string typically generated by messaging apps like Telegram or WhatsApp when a video is saved or forwarded .
If you received this from an unknown source, run it through VirusTotal before opening. MP4 files can occasionally be used to hide exploits. 1_4904768809975415234.MP4
Look at the chat history where you found the file. These IDs are often unique to the specific message or user who sent it. The filename is a generic numeric string typically
Are you trying to it, open it, or just know what's inside ? or just know what's inside ?