why is 64 added to the end of a typcast transformation?

    Select 
usertype, CONCAT(start_station_name, "to", end_station_time) As route
Count (*)
Round (avg(Cast(tripduration as int64)/60),2) As duration

–example typecast trip duration to integer includes 64.. but why?

Answer

This looks like BigQuery code.

In BigQuery, the integer type is called int64, meaning that it has 64 bits (or 8 bytes).

I’m not sure why it calls this int64 rather than simply int. I imagine it will disappear one day. It is a non-standard name and adds a needless inconsistency with other databases.