What number comes next in this sequence:

12 13 15 17 111 113 117 119 123 ==?==

Apparently, one side of a cat has more hair. The findings of the Swedish scientific establishment have been corroborated by a special enquiry by the BB Feline Federation. Many hair counts were taken of the side in question and consistently it was found to contain more hairs. The scientists determined that more hair was required on this side to insulate the cat from the elements while it was lying down. Perhaps you would like to examine a cat to confirm the findings. Before you do, can you guess which side of a cat has more hair?

The map below shows the street locations of a city. Position three police officers such that the entire length of every street can be seen by at least one officer.

Can you determine which number best completes this puzzle?