It's about 1,500,000 times as heavy as a Hippopotamus
In other words, 5.90 megatonnes is 1,570,000 times the weight of a Hippopotamus, and the weight of a Hippopotamus is 0.0000006370 times that amount.(Hippopotamus amphibius) (adult, male)
The average weight of an adult male hippopotamus ranges from 0.000003750 megatonnes. 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).
It's about 1,000,000 times as heavy as an Elephant
In other words, 5.90 megatonnes is 980,000 times the weight of an Elephant, and the weight of an Elephant is 0.000001000 times that amount.(for African bush elephant, Loxodonta africana) (Adult, bull)
A bull African bush elephant weighs about 0.00000610 megatonnes. Among African elephants, both males and females have tusks (whereas female Asian elephants, Elephas maximus, do not have tusks) which can grow to 3 m (10 ft) and typically weigh about 0.00000400 megatonnes
It's about 900,000 times as heavy as a Tyrannosaurus rex
In other words, 5.90 megatonnes is 920,000 times the weight of a Tyrannosaurus rex, and the weight of a Tyrannosaurus rex is 0.00000110 times that amount.(for FMNH PR2081, a.k.a. "Sue") (a.k.a. Tyrannosaurus, a.k.a. T-Rex) (estimated live weight)
The notable Tyrannosaurus specimen housed at the Field Museum of Natural History in Chicago, Illinois, "Sue," is estimated to have weighed about 0.00000640 megatonnes while alive. A renowned predator in popular culture, the teeth of tyrannosaurus rex were up to 33.02 cm (13 in) long.
It's about 500,000 times as heavy as an Anchor of a Cruise Ship
In other words, 5.90 megatonnes is 522,000 times the weight of an Anchor of a Cruise Ship, and the weight of an Anchor of a Cruise Ship is 0.000001920 times that amount.(for QE2 forward anchor, a.k.a. RMS Queen Elizabeth 2)
Each of the forward anchors of the RMS Queen Elizabeth 2 weighs 0.00001130 megatonnes. The anchor of the QE2 now sits in front of the Holyrood Church in Southampton, England, United Kingdom, along a pedestrian tourist route known as "the QE2 mile."
It's about 85,000 times as heavy as The Space Shuttle
In other words, the weight of The Space Shuttle is 0.0000120 times 5.90 megatonnes.(for Endeavour, a.k.a. OV-105, a.k.a. Orbiter Vehicle-105) (empty weight, excluding main engines)
When empty, the space shuttle Endeavour weighs 0.0000710 megatonnes. The shuttle's spacious cargo bay carried the Chandra X-ray Observatory into orbit in 1999 — a payload that weighed 0.0000200 megatonnes.
It's about 55,000 times as heavy as a Blue Whale
In other words, 5.90 megatonnes is 56,500 times the weight of a Blue Whale, and the weight of a Blue Whale is 0.00001770 times that amount.(Balaenoptera musculus)
Blue whales weigh between 0.000105 megatonnes. The largest mammal to have ever lived, blue whales feed almost exclusively on krill — tiny invertebrates weighing about 0.000000000001000 megatonnes each.
It's about 40,000 times as heavy as The Statue of Liberty (without base)
In other words, 5.90 megatonnes is 42,000 times the weight of The Statue of Liberty (without base), and the weight of The Statue of Liberty (without base) is 0.0000240 times that amount.(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 — the Statue's copper and framework only, excluding the base — is roughly 0.00014 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.