It's about 800 times the number of Population of Vatican City.
In other words, 660,000 is 784 times the count of Population of Vatican City, and the count of Population of Vatican City is 0.00128 times that amount.(a.k.a. Vatican City State, a.k.a. Stato della Città del Vaticano, a.k.a. Status Civitatis Vaticanae) (Rome, Italy) (2014 estimates; permanent residents only)
Vatican City, the seat of the Roman Catholic Church, is the smallest internationally recognized state in the world, with a population of just 842 people (according to a 2004 estimate). Each year, approximately 18 million tourists visit The City.
It's about 800 times the number of Kernels on an Ear of Corn.
In other words, the count of Kernels on an Ear of Corn is 0.001 times 660,000.(Corn, a.k.a. Maize; Kernel a.k.a. Seed) (average) (for Dent Corn, a.k.a. field corn)
It's about 900 times the number of Inductees in the Rock and Roll Hall of Fame.
In other words, 660,000 is 881 times the count of Inductees in the Rock and Roll Hall of Fame, and the count of Inductees in the Rock and Roll Hall of Fame is 0.00114 times that amount.(November, 2015 figures) (including individuals and groups)
It's about 1,000 times the number of Members of Parliament (The U.K.).
In other words, the count of Members of Parliament (The U.K.) is 0.001 times 660,000.(a.k.a. MPs) (2016 figures) (formally "Members of the House of Commons of the Parliament of the United Kingdom of Great Britain and Northern Ireland")
There are 650 Members of Parliament in the U.K. The Commons Chamber in the Palace of Westminster only has seating for 427 members, so those arriving late to House debates must stay standing.
It's about 1,500 times the number of Stores in the Mall of America.
In other words, the count of Stores in the Mall of America is 0.00077 times 660,000.(a.k.a. MOA, a.k.a. MoA, a.k.a. Megamall) (Bloomington, Minnesota) (2015 figures) (approximate)
Minnesota's Mall of America is home to 520 stores and attractions, including a wedding chapel, aquarium, and amusement park. Each year, an estimated 42 million people visit The Mall.
It's about 1,500 times the number of Olympic Gold Medals Won by the Soviet Union.
In other words, the count of Olympic Gold Medals Won by the Soviet Union is 0.000714 times 660,000.(a.k.a. Union of Soviet Socialist Republics, a.k.a. USSR, a.k.a. Сою́з Сове́тских Социалисти́ческих Респу́блик, a.k.a. CCCP) (a.k.a. Olympic Games, a.k.a. Jeux olympiques) (Summer and Winter Games grand totals; excluding Russian Federation Medals) (1952 thru 1988 figures)
During its 19 appearances in the Summer and Winter Olympic Games, the Soviet Union was awarded 473 gold medals. The Union holds the as-yet-unbroken record for gold medals in gymnastics, with 72.
It's about 2,000 times the number of Sesame Seeds on a Big Mac bun.
In other words, 660,000 is 1,900 times the count of Sesame Seeds on a Big Mac bun, and the count of Sesame Seeds on a Big Mac bun is 0.00053 times that amount.(McDonald's sandwich; approximate figures)