For security reasons, you may want to remove the WordPress version number from your WordPress website. The best way to do this is by adding the following code to your functions.php, preferably in a child theme:
[pastebin id="7ypdB0Mx"]
By far the best way to protect your WordPress blog is to always keep it up-to-date with the latest version, but adding this code will hide the version number from malicious spiders.