As an example Mathematica returns the the following number: 
 
  -5.65491*10^13
I would like to have it expressed as -565491000000000 
The obvious functions (to me) was to try 
 
  N[-5.65491*10^13,30]
  NumberForm[-5.65491*10^13,30]
but both leave the number with power notation kept. What is the reason?
Thanks.