If you are looking at a specific file named "9264.mobi," it is likely a digital book. If you are looking at it as a domain, it is a short-form numeric web address.
The string is also found in lists of that are or were available for registration. 9264 mobi
Shuxiang.org lists "9264.mobi" among thousands of other numeric domains. If you are looking at a specific file named "9264
This is a dynamic inventory count rather than a product name. 2. Domain Name Listings a specific device
The .mobi format is a legacy file type primarily used for older Amazon Kindle devices.
Could you provide on where you saw this name (e.g., a specific device, a website, or a file) so I can give you a more targeted review?