sudo launches command with escalated priviliges, username(or command) must be mentioned in sudoers file(directly, or indirectly via group)

dpkg is debian package manager

dpkg -i archive.deb (if you are root)
sudo dpkg -i archive.deb (if you are normal user under ubuntu)

maybe you got 32bit system, paste output of 'uname -a' and 'file *.deb', because for some reason dpkg doesnt recognize this.archive(maybe try to redownload it)