Ex-Prodigy’s Prodigious Memory Makes Recall of Numbers Easy as <i> Pi</i> : The Mind: In 1981, Rajan Srinivasen Mahadevan qualified for Guinness Book of World Records by reciting 31,811 digits of <i> pi</i> . But he can still forget where he put his keys.

It’s only fitting that Rajan’s story begin with a number: MYX1689, the number that started it all.

MYX554 was the license plate on the second car that pulled up to the house in Mangalore, India, where his parents were having a party. MYX558 was the third.

Some other 5-year-old might have sung a song or passed hors d’oeuvres to show off to the grown-ups: Rajan Srinivasen Mahadevan recited the license plates of all 40 cars in the order in which they had been parked.

That was the first anyone knew of Rajan’s astonishing memory. Twenty-seven years later, millions know of it, and there are days when he wishes he had sung a song or passed hors d’oeuvres.

A memory that can hold fast to 31,811 random numbers yet persistently forgets where keys have been left is a curious thing, a wondrous oddity that can bring opportunity, fame--perhaps even immortality--to its owner.

But what of the other things a man has--humor, creativity, intellect?

“This damn thing overpowers everything else, to a point,” Rajan said.

As a child, he said in the fluid, accented English he was reared with, “I used to be so lost in my own thoughts, I would talk to myself. It was hard to fit in. Other kids didn’t know what to make of me.”

Rajan’s memory was not unexpected. “It’s like John Lennon’s son and music,” he said. His father, a prominent surgeon, knows all 2,156 lines of William Shakespeare’s 154 sonnets.

“I was expected to make it big in life. But my academic career was like the drawing of a mountain range.”

Rajan tried engineering and business administration but felt no affinity for either. Then, someone suggested that he put his memory to the test by trying to win a place in the Guinness Book of World Records.

He began studying a computer printout of the first 200,000 decimal places of pi, the ratio between the circumference and diameter of a circle. Pi, the ultimate test of numerical memory, begins 3.14159, then continues on indefinitely with no known duplication or pattern. Two Columbia University mathematicians recently calculated pi to 480 million decimal places.

On June 12, 1980, Rajan flew to Chicago, where he stunned the fifth International Congress on Yoga and Meditation by reciting the first 10,000 numbers.

On July 5, 1981, he stood before a capacity crowd in a Mangalore meeting hall and rattled off numbers so quickly that the judges could barely keep up. For three hours and 49 minutes, his memory never faltered. Then, finally, a lapse: He forgot the 31,812th digit of pi--a 5.

Never mind. The record--20,013--had toppled. “On Feb. 16, 1983, I saw my name in the Book of Records, and I relaxed. That was the argument stopper. Until then, people could say: ‘So you have a good memory, so what?’

“But, from 1981 to 1987, I was the best in the world.”

In 1987, that honor went to Hideaki Tomoyori of Japan for reciting 40,000 digits in 17 hours, 21 minutes.

Still, memory expert Charles Thompson, a Kansas State University psychology professor, believes that Rajan’s memory is superior. “The Japanese guy made up a story, a mnemonic, to help him remember the numbers. His memory isn’t as good.”

In the lab where Thompson is studying Rajan’s memory, numbers flash past on a computer screen, one a second, and Rajan responds as if to music. He taps his feet and rocks rhythmically back and forth in his chair. Now and then, he jiggles his legs.

“There’s something about the way the numbers sound,” he said. “It’s not the way they look, it’s the way they sound.”

For example, Rajan finds the numbers in pi from the 2,901th to 3,000th places--81911979399520614196 and so on--particularly melodic. The series between 3,701 to 3,800--beginning 2332609729--is “very jarring.”

“Just as you can’t describe how you remember your phone number, neither can Rajan describe the process by which he remembers pi,” said Thompson, who, along with Jerome Frieman, an animal behaviorist, and Thaddeus Cowan, a cognitive psychologist, has been trying since January to figure it out.

“The first time we tested him, we said, ‘Oh my God!’ ”

Thompson thinks Rajan may have the most remarkable numerical memory known to science since “S,” a patient immortalized in clinical literature by A. R. Luria, the Soviet psychologist who studied him for nearly 30 years.

“S” was S. V. Shereshevskii, a Soviet newspaper reporter whose memory was discovered during the mid-1920s by an editor infuriated by his failure to take notes. “S” didn’t need to; he recalled everything he’d ever seen or heard.

What he couldn’t do was forget. Ultimately, unable to distinguish between conversations he had heard five minutes or five years before, “S” wound up in an asylum.

Rajan’s memory is exceptional only for numbers. In all other areas--names, faces, words--it is average. And, unlike “S,” he can forget, although “it is hard to willfully forget numbers.” Random numbers memorized one session come flooding back during another. Keeping the sequences straight requires discipline and concentration.

The tests he is undergoing are tedious. One test records ability to recall random digits that appear one a second on a screen. Ten is extraordinary; most people remember about seven. Rajan has recalled 64.

His is not a photographic memory but a highly structured system of some sort, Thompson said. “Rajan has pi stored in a very systematic way in his brain.”

As photocopied from a textbook, the numbers are organized in blocks of a thousand, with five blocks to a page. “We’ll say, ‘Give us the 18,336th digit of pi.’ ” The time it takes Rajan to search his memory for the right block of one thousand, then the right hundred and, finally, to pinpoint the number, hints at how these storage and retrieval processes work.

So does the occasional error. “If he makes a mistake, without fail he’ll be in exactly the right spot but a thousand digits off. Or, he’ll be in the right spot, only 10,000 digits off.” Right position. Wrong page.

A three-year National Institutes of Health grant pays for the research and for Rajan’s work toward a master’s degree in physiological psychology. “I want to know what neurons, what neurochemicals, are responsible for memory.”

The entire project “could be interesting and fun and yet not tell us a thing,” Thompson said. “What we hope is that we’re luckier than that. We hope his memory serves as a magnifying glass to show us how ordinary memory works. That will depend (on whether) we’re clever enough and lucky enough to do the right tests. There are a jillion tests.”

As random numbers rush past, Rajan sometimes makes fleeting associations with formulas learned in physics, chemistry or mathematics, with distances between cities, with ZIP codes or historic dates. Now and then, he chuckles softly at some private numerical joke. As the computer spits out 1,8,6,5, he murmurs “Lincoln,” who was assassinated that year.

Such connections don’t help him remember, he said. They are merely random thoughts that flit through his mind, small points of interest along the infinite journey through the decimal expansion of pi.

With testing over for another day, Rajan would much rather discuss something else--his talent for languages, artwork or cooking. A man is more than his memory, no matter how good it is.

“Thirty years from now, I want to see myself as well-rounded. I want to learn more languages, to learn musical instruments, to become as accomplished as possible. One way to grow as a human being is to develop your potential and expand mentally, then to help others develop as well.”

After 67 interviews in 56 days, he is tired of performing, tired of being asked if he could memorize a phone book as Dustin Hoffman did in “Rain Man,” tired of explaining that he is not an idiot savant.

Rajan’s growing celebrity is evident as he lopes along the wooded paths of the campus, a solitary figure deep in thought, reed-thin with dark eyes darting restlessly beneath inky curls. He shrugs off his reverie and responds jovially each time a student approaches to comment on this TV appearance or that magazine article.

He chose Kansas State for its psychology department as well as its generous financial aid, never imagining how lonely--how incongruous--he might feel in a small town in Kansas, no matter how friendly the town.

“There are far fewer distractions at KSU than at a UCLA or a Columbia,” he said philosophically. But he never misses a chance to travel to bigger cities, and the distances are among the numbers locked in his memory: 1,361 miles to New York, 1,294 to Washington; 498 to Dallas; 114 to Kansas City.

There are other foreign students at KSU, but most are men, and it isn’t male company he longs for as he trudges back and forth between the campus and his bachelor apartment. He shares it with another Indian student, who is usually at his girlfriend’s place. “I’m an incredibly lonely guy,” Rajan said.

It is hard to tell at Fast Eddy’s, the pool hall, where he seems to greet everyone. For 20 joyful minutes, he stretches gracefully over a table in the corner. His lanky arms send balls crashing as Dave Jenson watches approvingly.

The regulars know all about Rajan’s memory but “we try not to talk about it,” said Jenson, the owner’s son. “We take things in stride.”

Later, Rajan finds refuge with best friend Ruth Ridder, who feels a kinship based on her own British upbringing. Ruth, husband Tony and 3-year-old Hannah are “my American family,” Rajan said. He and Ruth take turns cooking Indian meals in her kitchen, where his memory is as irrelevant as a trick knee.

“He’s funny, he’s generous with his time and his finances. He’s also unreliable, forgetful and annoying in lots of ways. . . . He forgets our phone number constantly,” Ruth said.

“When it comes to his memory, I’m in the what’s-the-point category. I worry for him. He has a million acquaintances but he’s lonely. Too many people try to make him a performing animal. We try not to talk about it.”

In spite of himself, Rajan sometimes uses his memory to draw people to him. Once, he got a woman at a cafe to give him 57 random numbers.

“He drank two cappuccinos, read Interview magazine from cover to cover and discussed the ill way we treat Nicaragua,” Tony Ridder recalled. “Then, he repeated them to her. Backwards.”

Rajan admits to having hustled an occasional beer--a beer he would barely touch--but he said that is all in the past. These days, he confines his wizardry to the lab “so as not to contaminate the research.”

Besides, “Nobody will touch me with a barge pole.”

Tonight, it is his turn to cook, and he arrives at Ruth’s laden with spices from an international market. He chases everyone into the living room, strips off his shirt and spends the next hour alone in the kitchen, shrouded in steam.

“I close my eyes, and I’m back at my mother’s table eating supper,” he said, lost in a memory not of numbers but of how it feels to belong.