I totally understand what this error means and how to resolve.
My question is what does this number (148643705716736) referring to?
Date 5/7/2018 1:36:58 AM
Log SQL Server (Current - 5/7/2018 2:31:00 AM)
Could not allocate space for object 'dbo.SORT temporary run storage: 148643705716736' in database 'tempdb' because the 'PRIMARY' filegroup is full. Create disk space by deleting unneeded files, dropping objects in the filegroup, adding additional files to the filegroup, or setting autogrowth on for existing files in the filegroup.