It's about 10,000 times the number of Escalators in the State of Wyoming.
In other words, the count of Escalators in the State of Wyoming is 0.0001 times 21,000.(2013 figures)
It's about 4,000 times the number of Living U.S. Presidents.
In other words, the count of Living U.S. Presidents is 0.0003 times 21,000.(a.k.a. Presidents of the United States; a.k.a. Presidents of the United States of America; a.k.a. POTUS), (2016 figures) (including current)
It's about 2,500 times the number of Symphonies Composed by Beethoven.
In other words, 21,000 is 2,333.333333330 times the count of Symphonies Composed by Beethoven, and the count of Symphonies Composed by Beethoven is 0.000428571428572 times that amount.(a.k.a. Ludwig van Beethoven)
It's about 1,500 times the number of Living Kings and Queens.
In other words, the count of Living Kings and Queens is 0.00071 times 21,000.(2015 figures) (distinct Monarchs)
It's about 750 times the number of Countries in the European Union.
In other words, the count of Countries in the European Union is 0.0013 times 21,000.(a.k.a. EU) (2016 figures)
There are 28 member countries in the European Union, the latest member of which is Croatia. The EU is largely urban, with sixteen cities having a population of one million or more, and 75% of the population living in an urban area.
It's about 450 times the number of Teeth in a Great White Shark's Mouth.
In other words, the count of Teeth in a Great White Shark's Mouth is 0.0023 times 21,000.(Carcharodon carcharias) (average; including developing rows)
A Great White Shark has 48 exposed teeth on their upper and lower jaws. Behind these exposed teeth are developing teeth — up to 300 in about 5 rows. The sharks will continuously lose and replace the exposed teeth throughout their lives.
It's about 400 times the number of Countries in Africa.
In other words, 21,000 is 390 times the count of Countries in Africa, and the count of Countries in Africa is 0.0026 times that amount.(2016 figures) (sovereign states recognized by the UN only)
The continent of Africa includes 54 sovereign countries recognized by the United Nations as of 2016. It is the second-most populous continent in the world, with 1.1 billion inhabitants.