It's about thirty times as heavy as The Sears Tower
In other words, 5.90 megatonnes is 29.240 times the weight of The Sears Tower, and the weight of The Sears Tower is 0.0342 times that amount.(officially "Willis Tower" as of 2009) (Chicago, Illinois)
The Willis Tower weighs approximately 0.20180 megatonnes. The outer wall surface of the Tower is covered with black anodized aluminum panels which would total 110,000 sq. m (28 acres) if laid out together.
It's about eighteen times as heavy as The Empire State Building
In other words, 5.90 megatonnes is 17.80 times the weight of The Empire State Building, and the weight of The Empire State Building is 0.0562 times that amount.(New York City, New York)
The Empire State Building weighs approximately 0.3310 megatonnes. About 4% of the building's weight is its 6,000 cu. m (200,000 cu. ft) of limestone façade.
It's about seven-and-a-half times as heavy as The Golden Gate Bridge
In other words, 5.90 megatonnes is 7.330 times the weight of The Golden Gate Bridge, and the weight of The Golden Gate Bridge is 0.1360 times that amount.(San Francisco, California and Marin County, California) (Post 1986 weight reduction; total weight of bridge, anchorage, and approaches)
Following the completion of the 1986 project to eliminate excess material, the total weight of the Golden Gate Bridge — including its anchorages and approaches — is 0.8050 megatonnes. The two main cables in the spanning the bridge are spun out of a total of 129,000 km (80,200 mi) of wire.
It's about as heavy as The Great Pyramid of Giza
It's about 0.0000000000000010 times as heavy as The Earth
In other words, 5.90 megatonnes is 0.000000000000000987680 times the weight of The Earth, and the weight of The Earth is 1,012,500,000,000,000.000000000000000000000 times that amount.The mass of the planet Earth is 5,973,600,000,000,000.000000000000000000000 megatonnes. The element iron makes up about 32% of that mass, or 1,917,500,000,000,000.000000000000000000000 megatonnes.
It's about 0.000000000000000000003 times as heavy as The Sun
In other words, 5.90 megatonnes is 0.00000000000000000000300 times the weight of The Sun, and the weight of The Sun is 330,000,000,000,000,000,000.00000000000000000000000 times that amount.The sun has a mass of 1,999,999,999,999,999,966,445,568.000000000000000000000000000 megatonnes which represents 99.9% of the solar system's total mass. 98.7% of the sun's mass consists of hydrogen and helium — respectively the lightest and second-lightest elements in the universe.