The number appears as an issue or build identifier in various GitHub repositories , including Spyder IDE and Element Web , though these are typically unrelated to specific MP4 media files.
On the NCH Software forums, "20545" is identified as a thread ID for troubleshooting issues where VideoPad freezes while exporting slow-motion MP4 clips. 20545mp4
Sites such as Videezy use numeric identifiers for clips; for example, clip 20545 on their platform features stock footage of a foggy morning at sea. The number appears as an issue or build