It's about 300 times the number of Keys on a Piano.
In other words, 25,000 is 280 times the count of Keys on a Piano, and the count of Keys on a Piano is 0.0036 times that amount.(Moden layout; A0 to C7)
It's about 350 times the number of Submarines in the US Navy.
It's about 450 times the number of Countries in Africa.
In other words, the count of Countries in Africa is 0.0022 times 25,000.(2016 figures) (sovereign states recognized by the UN only)
It's about 500 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 0.0019 times 25,000.(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 900 times the number of Countries in the European Union.
In other words, 25,000 is 890 times the count of Countries in the European Union, and the count of Countries in the European Union is 0.0011 times that amount.(a.k.a. EU) (2016 figures)
It's about 1,500 times the number of Living Kings and Queens.
In other words, the count of Living Kings and Queens is 0.00059 times 25,000.(2015 figures) (distinct Monarchs)
As of 2015, the world has fifteen Kings and Queens reigning over 45 countries. Of all these, Queen Elizabeth the II is the only reigning Queen; she has monarchical authority over the sixteen of the Commonwealth nations.
It's about 3,000 times the number of Symphonies Composed by Beethoven.
In other words, 25,000 is 2,777.777777780 times the count of Symphonies Composed by Beethoven, and the count of Symphonies Composed by Beethoven is 0.00036 times that amount.(a.k.a. Ludwig van Beethoven)