Before his passing King David said to his son Solomon, "Know the God of your father with a perfect heart and a longing soul."
"A longing soul" = 613, the number of commandments in the Torah. To perform God's will in action requires "a longing soul."
613 is the 18th inspirational number (182 plus 172). "And you my son Solomon know… and a longing soul" = 2521, the 36th such number.