In my experience CTO is much more C than T, therefore focus on soft skills more than on technology skills. By the time CTO is eligible - the technology undergone a major shift from her comfort zone.

IMHO - it depends on type of programming you are targeting, I managed to thrive in IT with a little bit more than a high school math in the areas of business intelligence, high performance web and mobile apps, and system integrations. However there are areas where I am not likely to succeed e.g.: image/voice analysis, robotic algorithms, and high-end data science.

How about ionic, sent touch, meteor, cordova/phonegap, native script, and kendo ui to throw into the mix?