hi iphone 5s error 16

Get help with iOS update and restore errors - Apple Support

If you see error 16, you might have a hardware issue. Here's what to check:

1. Make sure that you have the latest version of iTunes.
2. Check for issues with third-party security software.
3. Make sure that your USB cable, computer, and network are reliable. Then try twice more to restore your iPhone, iPad, or iPod.
4. If you still see the error message, you can check for outdated or modified software or contact Apple support.

Get help with iOS update and restore errors - Apple Support