I'd like a money superpower please!

They have their brains Bruce Wayne is basically the best 'detective' in the dc universe, he is also has skill in forensic science, criminal psychology, chemistry, biology, physics, he speaks over 7 different languages fluently and is a master in at least 13 different martial arts and Tony Stark created a functioning AI (jarvis and ultron) among other things (I don't know as much about the marvel universe and Iron man). So while they do not have what you'd think of as a traditional superpower, like flight or telekinesis, their superpower is intelligence.

In that case Nikolai Tesla and Albert Einstein were superheroes, they are geniuses I'll give you that but no superhuman abilities.