India has observed National Mathematics Day every year since 2012 on Dec. 22, Ramanujan’s birth anniversary, to honor his lasting contributions to the field, according to the Hindustan Times.

Active in the early 20th century, Ramanujan made major contributions to mathematical analysis, number theory, infinite series and continued fractions despite having almost no formal training in pure mathematics.

He solved problems considered intractable at the time and produced thousands of elegant and surprising results, often without proof. He often said his equations had been bestowed on him in his dreams, according to Quanta Magazine.

In late 2025, researchers at the Indian Institute of Science found that Ramanujan’s methods for calculating pi, developed in 1914, are linked to modern physics, appearing in models used to describe turbulence, percolation and even black holes.

"Ramanujan’s motivation might have been very mathematical, but without his knowledge, he was also studying black holes, turbulence, percolation, all sorts of things," said Faizan Bhat, first author of the study and a former PhD candidate at the institute.

India's mathematician Srinivasa Ramanujan. Photo courtesy of CFAL India

From poverty to prodigy

Ramanujan was born in 1887 into a poor family in southern India. His father worked as a clerk in a garment shop, while his mother was a homemaker who also sang at local temples.

As a child, he struggled with speech and did not speak until the age of four. He was shy, overweight and had survived smallpox. But by age 10, he had developed a strong passion for mathematics. He quickly excelled, reading advanced, often outdated textbooks and conducting his own research into numbers and patterns while still in high school.

In 1904, he won a full scholarship to Government Arts College in Kumbakonam, in what is now Tamil Nadu state. But his obsession with mathematics led him to neglect all other subjects, and he lost the scholarship within a year. He later enrolled at another university in Madras, now Chennai, but failed again for the same reason.

After an arranged marriage in 1909, Ramanujan was forced to find work to support his family. He tutored students in mathematics and later secured a clerk’s job at the Madras Port Trust in 1912. He was so poor that he could only afford paper for final results and often worked out his calculations on stone slabs. Even then, he continued his research relentlessly.

Hoping to gain wider recognition, Ramanujan wrote to several British mathematicians in 1912, enclosing pages of his discoveries. "I have not trodden through the conventional regular course which is followed in a university course," he wrote, "but I am striking out a new path for myself."

Most ignored him. But in 1913, one letter reached G.H. Hardy, a leading mathematician at the University of Cambridge and one of England’s foremost experts in number theory and analysis. Hardy immediately recognized something extraordinary.

He was astonished that such work could come from someone with no formal mathematical training. Hardy and his colleagues believed Ramanujan possessed an instinctive grasp of mathematical truth unlike anything they had seen before.

They "defeated me completely; I had never seen anything in the least like them before," Hardy wrote in a letter to Ramanujan. "They must be true because, if they were not true, no one would have had the imagination to invent them." Recognizing his brilliance, Hardy arranged for Ramanujan to receive a fellowship at Cambridge.

Overcoming religious objections, Ramanujan arrived there in April 1914 and spent the next five years studying and collaborating with Hardy. In 1916, he earned a Bachelor of Science degree by research, the precursor to today’s PhD, and his work flourished. With Hardy’s help refining proofs and presentation, he published one major paper after another, according to research-based news publisher The Conversation.

Letters that Srinivasa Ramanujan exchanged with British mathematician G.H. Hardy. Photo courtesy of Trinity College, Cambridge

A lasting legacy

During his Cambridge years, he published 21 papers, including five with Hardy, covering number theory, infinite series and modular functions. Their Hardy-Ramanujan formula remains one of the best-known methods for estimating the number of ways an integer can be partitioned.

In 1918, he was elected a Fellow of the Royal Society, becoming only the second Indian to receive the honor. He was also the first Indian Fellow of Trinity College, Cambridge, and among the youngest fellows ever elected.

But his years in England were marked by severe illness. He struggled with the different climate, poor nutrition and depression caused by separation from his young wife and family. He had already suffered from serious liver problems before arriving in Cambridge, according to Indian news site The Federal.

As his physical and mental condition worsened, he attempted suicide and spent years in sanatoria for tuberculosis and vitamin deficiencies.

By early 1919, he had recovered enough to return to India, but his health continued to decline at home. Working in near isolation with only his wife assisting him, he kept pursuing mathematics until the end.

A few months before his death, he wrote his final letter to Hardy describing his discovery of mock theta functions, a new class of functions later found to have applications in modern physics, including counting black hole states in gravitational theory.

He died on April 26, 1920, at the age of 32. He left behind three notebooks and a "lost notebook", 100 loose pages of unproved discoveries from the final year of his life that were discovered in 1976 by mathematician George Andrews of Pennsylvania State University, containing unpublished results that continue to captivate mathematicians.

"This is the great thing about Ramanujan’s work," Shashank Kanade of the University of Denver, told Quanta Magazine. "It’s not just one identity he discovered, and a dead end. It’s always the tip of an iceberg. You just have to follow it through."

His life story inspired the 2015 British biographical drama film "The Man Who Knew Infinity," directed by Matthew Brown, while another film, "Dreams of Ramanujan," is being produced by director R. S. Prasanna.

In Ramanujan’s obituary, Hardy reflected that he might have become an even greater mathematician had he been "caught and tamed a little" in his youth.

"He would have discovered more that was new, and that, no doubt, of greater importance.

"On the other hand, he would have been less of a Ramanujan, and more of a European professor, and the loss might have been greater than the gain."