In specific technical tests, numeric strings may represent file sizes; for example, "23816K" has been used to denote a specific compressed file size ( ) in Linux compression tests. Safety and Handling Recommendations

Could you provide on where you found this file or what you believe it contains? Knowing the website of origin or the file's size would help in identifying it. rar file problem.! - Adobe Community

Since the origin of "23816.rar" is ambiguous, follow these security best practices if you have encountered this file:

Some servers assign sequential ID numbers to files for internal database tracking.

Mail clients or security gateways sometimes rename attachments with a numeric string if the original name is obscured or needs to be unique.