To check the number of CPUs in HP-UX, use the `prtconf` command. This command displays a list of all the hardware devices installed on the system, including the CPUs. The output of the `prtconf` command will vary depending on the system, but it will typically include a line that looks like the following:
Processor Information--------------------# of CPUs: 4
The number after the “#” symbol is the number of CPUs on the system. In this example, there are 4 CPUs.