What's the deal with numbers?

The Catechism of the Catholic Church states that superstition is not supposed to be practiced and it is a violation of the 1st Commandment to honor God about all else. However, there's always something going on like a 9 day novena or a 40 day fast or a request to return to a particular grotto on the 11th of each month. Then there's other significant numbers like 3 and 7 and 12 which are supposed to mean something and spooky numbers like 6 and 666. So, where is the line between superstition and awe at the way God orders things mightily?