It's about 35,000 times as heavy as a Grain of Sugar
In other words, 0.021 kilograms is 33,600 times the weight of a Grain of Sugar, and the weight of a Grain of Sugar is 0.00002980 times that amount.(a.k.a. white sugar, a.k.a. white refined sugar, a.k.a. table sugar, a.k.a. sucrose, a.k.a. saccharose)
A grain of sugar weighs approximately 0.0000006250 kilograms. Sugar consumption varies widely by country; the average citizen of the United States consumes about 61.2 kg of sugar each year.
It's about 70,000 times as heavy as a Poppy Seed
In other words, the weight of a Poppy Seed is 0.0000140 times 0.021 kilograms.(Papaver somniferum)
Fifty percent oil by weight, a poppy seed weighs approximately 0.000000300 kilograms. The true pigment of a poppy seed is brown in color, while the characteristic bluish color is an optical illusion caused by a layer of calcium oxalate crystals refracting light rays.
It's about one-eighty-thousandth as heavy as a Car
It's about one-ninety-thousandth as heavy as a Giraffe
In other words, 0.021 kilograms is 0.00001090 times the weight of a Giraffe, and the weight of a Giraffe is 91,700 times that amount.(Giraffa camelopardalis reticulata) (adult, male, maximum of range)
An adult, male giraffe can weigh up to 1,930 kg. Reaching 5.5 m (18 ft) in height by adulthood, giraffe calves can grow as much as 3 cm (1 in) per day.
It's about one-one-hundred-thousandth as heavy as a Rhinoceros
In other words, 0.021 kilograms is 0.00001000 times the weight of a Rhinoceros, and the weight of a Rhinoceros is 100,000 times that amount.(for Black rhinoceros, Diceros bicornis) (Adult, male)
An adult black rhinoceros weighs between 1,400 and 2,800 kg. Rhinoceros are extremely aggressive — nearly one of every two males will die as a result of fighting with other rhinoceros.
It's about one-one-hundred-fifty-thousandth as heavy as The Tongue of a Blue Whale
In other words, the weight of The Tongue of a Blue Whale is 130,000 times 0.021 kilograms.(Balaenoptera musculus) (adult)
The tongue of a Blue Whale can weigh up to 2,700 kilograms. Despite their tremendous size, blue whales feed almost exclusively on tiny crustaceans called krill and cannot swallow anything much larger than a beach ball.
It's about one-two-hundred-thousandth as heavy as a Hippopotamus
In other words, 0.021 kilograms is 0.00000560 times the weight of a Hippopotamus, and the weight of a Hippopotamus is 179,000 times that amount.(Hippopotamus amphibius) (adult, male)
The average weight of an adult male hippopotamus ranges from 3,000 to 4,500 kg. Appearances to the contrary, adult hippos cannot swim or float in water; they actually move by leaping and walking across lake bottoms at about 8 kph (5 mph).