LastPass – Why is There a Number Under the Icon in Chrome?

LastPass stores data in various places depending on your operating system and browser.

This information is taken from this LastPass FAQ Article

Windows

• IE & Firefox
  • AppData%\..\LocalLow\LastPass\ or %AppData%\..\Local Settings\Application Data\LastPass\
• Chrome
  • %AppData%\..\Local\Google\Chrome\User Data\Default\databases\chrome-extension_hdokiejnpimakedhajhdlcegeplioahd_0\
• Safari
  • %AppData%\..\Local\Apple Computer\Safari\Databases\safari-extension_com.lastpass.lpsafariextension-n24rep3bmn_0\

OS X

• Safari & Firefox
  • ~/Library/Application Support/LastPass/
• Firefox (non-binary
  • Firefox profile directory
• Chrome
  • ~/Application Support/Google/Chrome/Default/databases/chrome-extension_hdokiejnpimakedhajhdlcegeplioahd_0/

Linux

• Firefox
  • ~/.lastpass/
• Chrome
  • ~/.config/google-chrome/Default/databases/chrome-extension_hdokiejnpimakedhajhdlcegeplioahd_0/

Firefox on other platforms utilizes the Firefox profile directory. You can back these directories up and they will contain the latest copy of your data. Be aware that on Windows, Protected Storage is used to additionally encrypt your data so you'll need to ensure that your Windows profile is also backed up. Your data is also backed up at LastPass.com, and a copy is on any other device or computer you use so this isn't required.

Your data is also securely synced with the LastPass servers. When you make updates to your LastPass account, whether in a browser plugin, a mobile app, or the website, the updates are reflected on the LastPass servers as well. If your hard drive ever crashes, or your laptop is stolen, you can easily regain access to your accounts by reinstalling the plugin (https://lastpass.com/download.php) and logging in with the same email and master password.

There's a setting in LastPass preferences called "Share login state between other browsers". It's located in the advanced section (list on the left). Uncheck it & save the settings.