As a Time Lord, the Master has an unnaturally long life expectancy. At one point he had already used up the limited number of "regenerations" that Time Lords can undergo to rejuvenate their bodies and was physically decaying, but he managed to somehow possess the body of another person to renew himself.
The Master has a genius-level intellect and possesses detailed knowledge of multiple scientific and technological fields. He is also well-traveled and able to fend for himself on nearly any civilized planet.
At some points in his history, the Master possesses a TARDIS that enables him to travel through time and space. While there is no indication that its chameleon circuit is damaged, it often resembles some variation of a grandfather clock. This may just be a personal preference, as in "Castrovalva" it was seen in the form of a fireplace.
The Master frequently carries a weapon that kills by molecular compression, turning the victim into a miniature, doll-like corpse. He recently constructed a "laser screwdriver" with a variety of uses.