Take the numbers 220 and 284. They seem to have little in common aside from the fact that they are both even. Once factored, however, their relationship becomes clear. The factors of 220 are 1, 2, 4, 5, 10, 11, 20, 22, 44, 55, 110 and 142. Adding them all together yields 284. Apply the same process to 284 and the sum equals 220. These are called “amicable numbers,” and they are incredibly rare. Surprisingly, I learned about this mathematical oddity not in a math textbook but in a delightful novel.

“The Housekeeper and the Professor,” written by Yoko Ogawa and translated from Japanese by Stephen Snyder, is a novel about an elderly math professor being cared for by a housekeeper and her son. The professor was in a car accident 15 years before the story begins, and he can only remember things that happened either before the accident or in the last 80 minutes. These lapses in memory cause him to come up with many odd schemes to get through his day, including writing things down on scraps of paper and pinning them to his clothes. From this unusual premise, Ogawa weaves an exquisite narrative. 

In addition to the many math concepts featured in the novel, the plot is intriguing and engaging. The story revolves around the execution of the Housekeeper’s plan to take the Professor to see his favorite professional baseball team play, a task complicated by the Professor’s memory lapses. The math in the novel draws the reader and the characters together, creating a coherent narrative. 

Ogawa manages to turn math into art, and number theory becomes the poetic center of the book.

“[Number theory] is sometimes called the ‘Queen of Mathematics’… Noble and beautiful like a queen, but cruel as a demon… I studied the numbers we all know, 1, 2, 3, 4, 5, 6, 7… and the relationships between them,” the Professor says when explaining to the Housekeeper the type of math he studies.

Math forges connections between a small set of endearing characters. The forgetful Professor, who has hundreds of tiny reminder notes attached to his clothes, teaches his housekeeper and her son to love the hidden mysteries of numbers. He nicknames her son Root because his flat head reminds him of the square root symbol.

The process of discovery of the hidden connections between things that are seemingly unrelated adds drama to this quiet but astounding book. “The Housekeeper and the Professor” manages to artfully blend the disparate subjects of literature and mathematics in a brief, achingly beautiful novel. π