To display the previous and current run level, use the runlevel command, for example:

# runlevel
N 5

If there is no previous run level, N is displayed. In this example, the current run level is 5.

The who -r command also displays the current run level, for example:

# who -r
run-level 5  2013-03-15 09:24

For more information, see the runlevel(8) and who(1) manual pages.