Variable: org-default-priority
org-default-priority is an alias and customizable for
org-priority-default, defined in org.el.gz.
Value
66
Documentation
The default priority of TODO items.
This is the priority an item gets if no explicit priority is given.
When starting to cycle on an empty priority the first step in the cycle
depends on org-priority-start-cycle-with-default. The resulting first
step priority must not exceed the range from org-priority-highest to
org-priority-lowest which means that org-priority-default has to be
in this range exclusive or inclusive to the range boundaries. Else the
first step refuses to set the default and the second will fall back on
(depending on the command used) the highest or lowest priority.