While trying to import logs, I kept running across an error stating that the visit_total_time was out of range. Looking at the number trying to be inserted (65842) vs the column type (smallint, max of 65535), this is only 18.2 hours... crazy but some people might be on that long.
Changed the column to mediumint in my database to give a total of 16777215 (unsigned) seconds or 6.3 months
In b420123: Fixes #3817 Capping visit_total_time
Thanks for the report!
PS: this visit is most likely a bot or browser with auto refresh