From what I've read, Ramanujan is a contender for the greatest math genius who ever lived. Contemporary mathematicians are still playing catch-up with his insights.
What's striking is that he himself didn't take personal credit for his insights. He attributed his insights to religious dreams. A devout Hindu, he said the Hindu gods gave him visions of mathematical formulas. When he awoke, he simply jotted down what he remembered. He was just a scribe of the Hindu muses (as it were). And, in fact, he only wrote down a fraction of what he saw in his dreams, because that's all he remembered.
This raises the question of how we should interpret his claims. On the one hand, we might consider a naturalistic explanation. Discount his self-testimony. On this view, mathematical intuition operates at a subliminal level. But because Ramanujan has internalized his religion, his mathematical intuition manifested itself in these cultural categories. That's how he tapped into his subconscious. Dreams are part of our subconscious mental life, which intersects with intuition.
On the other hand, we might take his explanation more seriously. What if he really was tapping into a superior mind? What if the Hindu "gods" did, in fact, reveal these insights?
Of course, from a Christian standpoint, we'd say that's occultic. But it's possible that his mathematical discoveries were, indeed, supernatural in origin. Perhaps he was truly "inspired." The supernatural isn't confined to the divine. And the notion that genius is a type of possession is a very old notion.
Assuming that's the case, then he wasn't a genius after all. He may have been a man of average or even below average intelligence who was channeling the dark side. A medium. His own contribution was merely instrumental.