The DHCP addresses will likely change if you shut down all computers and the printer, then restart them. The Static IP address is a permanent address that is used every time and is not assigned by the DHCP server (your router).
You can administer this printer (4000n) by accessing the embedded web server of the printer. From your browser enter the IP address of the printer.
HP Printer Utility - this HP software does not provide a laserjet print utility for Mac OS X. it is advised to access the printers embedded web server (EWS) to configure and administer the printer. The EWS can be accessed directly from Safari browser via Bonjour tab or by entering the printers IP address into any web browser.