Titans — Edward W. Robertson

Rob Dunbar is the world's best history professor. And with good reason: he's been alive for three thousand years, keeping his existence a secret since before the days of Athens. But a stranger named Baxter has a better use for Rob's vast expertise. Baxter's looking to found a mining company in the Asteroid Belt. In exchange for Rob's help, he'll try to unravel the mystery of Rob's origin. As they're getting their outfit off the ground, they come under covert attack by HemiCo, a powerful Mars-based corporation. And Rob learns Baxter has a secret of his own -- he's not human. He's a highly illegal AI. Developed by HemiCo in the wilds of Mars, the first AI escaped decades ago. They've been fighting a shadow war against their creators ever since. Dragged to Mars, Rob is thrown into the center of the fight -- and becomes the unlikely leader of a revolution that will change the course of human history amongst the stars.