The reference regarding the spiritual significance of numbers is taken from Appendix 10 , Companion Bible.
The numbers you saw are divisible by 11, which signifies disorder and disorganization.  Multiples of numbers generally denote levels of intensity of that number.
Significant here is that the US was attacked on 9/11, 9=judgement, 11=disorder.  We are approaching 3 years since the original attacks.  3=completeness, which may prompt further actions to "complete" the original 9/11 attacks.
 
I' m sure there are many interpretations of numbers.  Given the context that we live in, this is mine.
 
JM