Ubuntu – Uninstall virtualenv which was installed through sudo pip

***********Update2******************

Tried and successfully created a virtual environment using virtualenv.

[08:05 USER@system ~] > mkdir test_virtual
[08:05 USER@system ~] > virtualenv test_virtual/
New python executable in /home/USER/test_virtual/bin/python
Installing setuptools, pip, wheel...done.
[08:05 USER@system ~] > ls test_virtual/
bin  include  lib  local  pip-selfcheck.json

***********Update1******************

As requested here are the pastebin links to pip list and pip3 list.

***********Original******************

I installed virtualenv using sudo pip install virtualenv, which after reading on several answers here is actually not a good practice. When I try to uninstall it (mainly because I'm planning to go the anaconda way and I don't like extra dirt that I don't use on my system) I get the following error:

(09:20 USER@system ~) > sudo pip uninstall virtualenv
The directory '/home/USER/.cache/pip/http' or its parent directory is not owned by the current user and the cache has been disabled.
Please check the permissions and owner of that directory.
If executing pip with sudo, you may want sudo's -H flag.
Cannot uninstall requirement virtualenv, not installed
The directory '/home/USER/.cache/pip/http' or its parent directory is not owned by the current user and the cache has been disabled.
Please check the permissions and owner of that directory.
If executing pip with sudo, you may want sudo's -H flag.

When I use sudo -H flag, I get this:

Cannot uninstall requirement virtualenv, not installed

But I confirmed that virtualenv is still installed:

(09:25 USER@system ~) > which virtualenv
virtualenv is /usr/local/bin/virtualenv
virtualenv is /usr/local/bin/virtualenv
virtualenv is /usr/local/bin/virtualenv
virtualenv is /usr/local/bin/virtualenv

How do I uninstall virtualenv from my system?

Thanks.