Numfmt command reads numbers in various representations and converts them to human representation on the command-line. Using Numfmt, you can convert numbers from to human readable form. It (GNU coreutils package) is pre-installed in your Ubuntu Linux distribution.
Numfmt Examples:
Convert Numbers to Human Readable Format in Ubuntu:
numfmt --to=si 6600000
si: International System of Units (SI) standard
Convert Numbers from Human Readable to Numeric:
numfmt --from=si 2.2G
For the complete usage details run below command.
man numfmt
You can also check here