By age three, budding Hungarian mathematician Paul Erdos had already taught himself to calculate how many days until his mother’s next vacation. An impressive feat for a toddler, to be sure, but the number was crucial to Paul: His father had been taken prisoner in World War I — he would be held in Siberia for six years — so Paul’s mother worked round the clock to pay the bills while also acting as her son’s sole caretaker. Paul, often left alone, taught himself to read with the math textbooks his parents had used when they both worked as teachers. Little did that lonely child know, his future would be spent making community connections that would impact the entire world of mathematics.

Paul was already making a name for himself by age 17. Despite the fact that Jews were barred from higher education in Hungary, he earned entry to university. Within four years, he’d graduated with not only a Bachelors but with a PhD in mathematics. With few options open to him because he was Jewish, Paul accepted a fellowship in Manchester, England in 1934 — a move that may have saved his life during the Holocaust. It wasn’t until Budapest’s 1945 liberation that Paul discovered the fate of his family: Though his mother had survived in hiding, his father had died of a heart attack and many of their relatives had perished.

Paul quickly became one of the world’s preeminent mathematicians, eventually publishing over 1,500 mathematics papers — the most of any mathematician ever. Even so, he became nearly as famous for his quirky lifestyle as for his genius. Because Paul never found one place to call home, but rather chose to live his life out of a suitcase: He was a globetrotting transient who bounced from one mathematician’s home to the next, often staying for months and requiring his host to feed and care for him. But in his travels, Paul managed to unite the global mathematics community. Collaborating on countless theorems, he connected distant ideas: He might tell a Dublin mathematician about the work of another in Wichita, initiating major breakthroughs. In fact, Paul’s endless collaborations inspired mathematicians to create the Erdos Number, a kind of “Six Degrees of Kevin Bacon,” which indicates how far any mathematician is from Paul through a chain of co-authorships. The smaller the number, the closer your association with Paul and his ideas — and of note, Fields Medalists and Nobel laureates tend to have small Erdos numbers.

Though as an adult Paul stopped practicing religion, he always proudly called himself a Jew. He believed that G-d has an infinite book filled with the most beautiful proofs to every single math problem, which he hoped to study in the afterlife. After a lifetime of saying he wished to die while solving a theorem, Paul nearly got his wish. He passed away in 1996 at the age of 83, just hours after cracking one last geometry problem at a conference in Warsaw.