It's about one-thirty-thousandth as heavy as The Brooklyn Bridge
In other words, 0.000000420 megatonnes is 0.000031530 times the weight of The Brooklyn Bridge, and the weight of The Brooklyn Bridge is 31,720 times that amount.(a.k.a. New York and Brooklyn Bridge) (Manhattan and Brooklyn, New York City, New York) (total weight)
The total weight of the Brooklyn Bridge is approximately 0.01332 megatonnes. In a promotional event to prove the bridge's stability shortly after it opened, entertainer P. T. Barnum led a parade of 21 elephants across it in May of 1884.
It's about 35,000 times as heavy as a Battery (AAA)
In other words, the weight of a Battery (AAA) is 0.0000290 times 0.000000420 megatonnes.(Alkaline)
An "AAA" size battery weighs 0.0000000000120 megatonnes. Batteries are named by the American National Standards Institute (ANSI) Committee C18 and AAA batteries were given their name because they were smaller than the "AA" and "A" size batteries which were invented first.
It's about one-sixty-thousandth as heavy as The Statue of Liberty
In other words, the weight of The Statue of Liberty is 58,800 times 0.000000420 megatonnes.(a.k.a. Liberty Enlightening the World, a.k.a. La Liberté éclairant le monde) (total weight, including foundation)
The total weight of the Statue of Liberty, including her base is roughly 0.0246 megatonnes. The statue was designed using an optical trick known as "forced perspective" to make the statue appear proportionally correct when viewed from its base and is, in actuality, disproportionately large at the top.
It's about 60,000 times as heavy as an Eye (Human)
In other words, 0.000000420 megatonnes is 59,000 times the weight of an Eye (Human), and the weight of an Eye (Human) is 0.0000170 times that amount.(adult)
A fully developed eye (in a person over the age of thirteen), weighs about 0.00000000000710 megatonnes. The pupil of the eye varies depending on the amount of light it is exposed to, but typically measures about 4 mm across.
It's about 75,000 times as heavy as a Quarter
In other words, 0.000000420 megatonnes is 74,070 times the weight of a Quarter, and the weight of a Quarter is 0.00001350 times that amount.(United States quarter-dollar coin) (a.k.a. Quarter dollar, a.k.a. America the Beautiful quarter, a.k.a. two bits)
The America the Beautiful series quarters, which began to enter circulation in 2017, weigh 0.000000000005670 megatonnes each. In answer to the common riddle, there are 119 ridges around the edge of the coin in its current design.
It's about 85,000 times as heavy as a sheet of Paper
In other words, the weight of a sheet of Paper is 0.0000120 times 0.000000420 megatonnes.(for US Letter, a.k.a. ANSI A; 215.9mm by 279.4mm (8.5 in x 11 in); 20lb)
The weight of a ream (500 sheets) of 0.00000000910 megatonnes, 8.5 inch x 11 inch paper is 0.00000000200 megatonnes, each sheet weighing 0.00000000000500 megatonnes. Paper of this size has a thickness of 0.004 caliper (0.1 mm).
It's about 100,000 times as heavy as a Die (Dice)
In other words, the weight of a Die (Dice) is 0.00001000 times 0.000000420 megatonnes.(for six-sided, 16 mm, rounded cube)
A die, of the size most commonly used in board games and casinos, typically weight 0.00000000000410 megatonnes. The use of dice and dice-like tools predates written history, with the oldest known examples belonging to a 5,000-year old backgammon set uncovered during an archaeological dig in modern-day Iran.