Berlin - German voters go to the polls on Sept. 24 and Angela Merkel is hoping to win a mandate for a fourth term as chancellor. By now everybody knows that the 63-year-old leader grew up in East Germany, trained as a scientist and opened the country's doors to a large number of migrants in 2015.But here are five things you might not yet know about Merkel:SLEEPLESS IN BERLINMerkel is well known for her ability to stay alert during important late-night negotiations. That's a big advantage when world leaders have to grapple with complex topics like climate change, state bailouts or peace talks in the early hours of the morning. Merkel says she needs her sleep just like everyone else but that she has the ability to survive on very little for a short while. "I've got certain camel-like abilities," she once told the German women's magazine Brigitte.NOT THE BEST COMMUNIST STUDENTLike all East German students, Merkel had to take compulsory courses in Marxism-Leninism. But unlike her studies in physics, which she completed "magna cum laude," her efforts in communist ideology rated merely "sufficient." Later, while working at the Academy of Sciences in East Berlin, the future chancellor was in the communist youth organization and held the title "Secretary for Agitation and Propaganda," according to biographers Guenther Lachmann und Ralf Georg Reuth. Merkel has never denied this, but said her task mainly involved organizing book readings and visits to the theatre.GREEN THUMB, NO FRILLSThe chancellor isn't known for leading an opulent life. In fact, she lives in an ordinary apartment in the center of Berlin, owns a small country house in the Uckermark region north of the capital and grows her own vegetables.BIG TIME SOCCER FANEvery German leader is required to cheer the national soccer team — it's the country's favorite sport, after all — and Merkel is no exception. Yet the chancellor takes her role as cheerleader more seriously than most politicians. Whenever she can, she'll pop into the dressing room to wish the German players good luck.THE RIGHT CHEMIST(RY)Merkel's second husband, quantum chemist Joachim Sauer, has largely shunned the limelight. In the early days of her chancellorship, he only appeared at Merkel's side during her annual pilgrimage to the Bayreuth opera festival, prompting one magazine to dub him the "Phantom of the Opera." Nothing is known about his politics. But Merkel once told an interviewer that after one parliamentary debate Sauer noted disapprovingly that she'd been wagging her finger the whole time.