It's about 0.0000000000000000002 times as heavy as The Sun
In other words, 400,000,000 tonnes is 0.00000000000000000020 times the weight of The Sun, and the weight of The Sun is 5,000,000,000,000,000,000.00000000000000000000 times that amount.The sun has a mass of 2,000,000,000,000,000,000,000,000,000 (2 octillion) tonnes 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.
It's about 0.00000000000007 times as heavy as The Earth
In other words, 400,000,000 tonnes is 0.000000000000066961 times the weight of The Earth, and the weight of The Earth is 14,934,000,000,000 times that amount.The mass of the planet Earth is 5,973,600,000,000,000,000,000 (5.973 sextillion) tonnes. The element iron makes up about 32% of that mass, or 1,917,500,000,000,000,000,000 (1.917 sextillion) tonnes.
It's about 70 times as heavy as The Great Pyramid of Giza
In other words, 400,000,000 tonnes is 68 times the weight of The Great Pyramid of Giza, and the weight of The Great Pyramid of Giza is 0.02 times that amount.(a.k.a. Pyramid of Khufu, a.k.a. Pyramid of Cheops) (Cairo, Egypt)
The Great Pyramid of Giza has an estimated mass of 5,900,000 tonnes. The 2,300,000 stones used in the construction of the pyramid weighed an average 2.27 tonnes and were quarried from distances of up to 805 km (500 mi) away.
It's about 500 times as heavy as The Golden Gate Bridge
In other words, 400,000,000 tonnes is 497 times the weight of The Golden Gate Bridge, and the weight of The Golden Gate Bridge is 0.0020 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 805,000 tonnes. 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 1,000 times as heavy as The Empire State Building
In other words, 400,000,000 tonnes is 1,210 times the weight of The Empire State Building, and the weight of The Empire State Building is 0.00083 times that amount.(New York City, New York)
The Empire State Building weighs approximately 331,000 tonnes. About 4% of the building's weight is its 6,000 cu. m (200,000 cu. ft) of limestone façade.
It's about 2,000 times as heavy as The Sears Tower
In other words, 400,000,000 tonnes is 1,982 times the weight of The Sears Tower, and the weight of The Sears Tower is 0.000505 times that amount.(officially "Willis Tower" as of 2009) (Chicago, Illinois)
The Willis Tower weighs approximately 201,800 tonnes. 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 3,500 times as heavy as The CN Tower
In other words, 400,000,000 tonnes is 3,392.4 times the weight of The CN Tower, and the weight of The CN Tower is 0.0002948 times that amount.(a.k.a. La Tour CN, a.k.a. Canadian National Tower, a.k.a. Canada's National Tower) (Toronto, Canada)
The CN Tower weighs approximately 117,910 tonnes. The Tower is home to the world's highest glass floor — a viewing area that allows visitors to look straight down 342 m (1,120 ft) to the ground below.