According to the Google Drive SDK, the size and MD5 hash of files is available through the API. Each resource (file) has an md5Checksum and a fileSize:
md5Checksum (string):An MD5 checksum for the content of this file. This is populated only for files with content stored in Drive.
fileSize (long):The size of the file in bytes. This is populated only for files with content stored in Drive.
How can I access them through Google's web interface? I'd like to avoid coding my own interface just for this.