there is not that much usable space on a 64GB device. you have a total of 62.2GB. A 64GB storage device only has around ~57 to 59GB of usable storage space.
After you cut down to a amount of data that you can actually store on the drive try transferring in smaller chunks. That is quite a bit of data. Transferring in that large of a transfer at one can be problematic some times.
