If this was found in a specific folder (e.g., a "Downloads" or "Backup" folder), the surrounding files may provide context as to which application generated it.
The number 1639885504 is a Unix timestamp. When converted, it represents Saturday, 18 December 2021, 22:25:04 UTC . 1639885504.zip
if the source is unknown. Zip files are frequently used to mask malware, scripts, or ransomware. If this was found in a specific folder (e
Services like Google Takeout or private FTP transfers often use numerical strings for temporary batch downloads. Security Warning a "Downloads" or "Backup" folder)