I have a doctorate in computer security which was pretty much all mathematics and I would definitely hire someone like you. You'd need, of course, to show that you had an aptitude for programming, but at my company, CloudFlare, we have some big (as in interesting) problems that need solving. These big problems need smart people; a PhD in mathematics is an indicator of being fairly smart in a way we could likely use.
What sort of mathematics did you do? Clearly, if you have a good grounding in statistics there are lots of opportunities and the whole field of machine learning is mathematics that's been implemented in code.