It's about 1,500,000 times the number of Keys on a Piano
In other words, the count of Keys on a Piano is 0.000000590 times 150,000,000.(Moden layout; A0 to C7)
It's about 2,000,000 times the number of Submarines in the US Navy
In other words, 150,000,000 is 2,100,000 times the count of Submarines in the US Navy, and the count of Submarines in the US Navy is 0.000000480 times that amount.(a.k.a. Subs) (includes all types, all classes) (2015 figures)
The United States Navy maintains a fleet of 72 active submarines. A typical submarine goes to sea with a crew of about 140.
It's about 2,500,000 times the number of Countries in Africa
In other words, the count of Countries in Africa is 0.000000370 times 150,000,000.(2016 figures) (sovereign states recognized by the UN only)
It's about 3,000,000 times the number of Teeth in a Great White Shark's Mouth
In other words, 150,000,000 is 3,100,000 times the count of Teeth in a Great White Shark's Mouth, and the count of Teeth in a Great White Shark's Mouth is 0.000000320 times that amount.(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 5,500,000 times the number of Countries in the European Union
In other words, the count of Countries in the European Union is 0.000000180 times 150,000,000.(a.k.a. EU) (2016 figures)
It's about 10,000,000 times the number of Living Kings and Queens
In other words, the count of Living Kings and Queens is 0.0000001000 times 150,000,000.(2015 figures) (distinct Monarchs)
It's about 15,000,000 times the number of Symphonies Composed by Beethoven
In other words, 150,000,000 is 16,666,666.66670 times the count of Symphonies Composed by Beethoven, and the count of Symphonies Composed by Beethoven is 0.00000005999999999990 times that amount.(a.k.a. Ludwig van Beethoven)