
It's about 2,500 times as heavy as a Billiard Ball.
In other words, 404 kilograms is 2,478.3792395879 times the weight of a Billiard Ball, and the weight of a Billiard Ball is 0.00040348949992265 times that amount.
(Americanstyle, WPA specifications)
It's about 3,000 times as heavy as a Baseball.
In other words, 404 kilograms is 2,780.6206102694 times the weight of a Baseball, and the weight of a Baseball is 0.00035963194558323 times that amount.
(MLB rules)
It's about 3,000 times as heavy as a Battery (D).
In other words, 404 kilograms is 2,990 times the weight of a Battery (D), and the weight of a Battery (D) is 0.000334 times that amount.
(Alkaline)A "D" size battery weighs 0.135 kilograms. The D size battery is the oldest of the modern battery sizes, first invented by the National Carbon Company in 1898.
It's about onethreethousandth as heavy as a Tree (Sierra Redwood).
In other words, 404 kilograms is 0.00031 times the weight of a Tree (Sierra Redwood), and the weight of a Tree (Sierra Redwood) is 3,200 times that amount.
(a.k.a. Giant Sequoia, a.k.a. Sierran redwood, a.k.a. Wellingtonia, a.k.a. "Big Tree", Sequoiadendron giganteum)The weight of wood in a Giant Sequoia is 1,300,000 kilograms. General Sherman, a specimen in Sequoia National Park in Visalia, California, is the largest tree in the world by volume, with an estimated weight of about 1,900,000 kilograms.
It's about 4,500 times as heavy as a Deck of Cards.
In other words, the weight of a Deck of Cards is 0.00023 times 404 kilograms.
(ISO 216 B8 size, a.k.a. "poker size" 63 x 88 mm, 52card deck)
It's about 6,000 times as heavy as a Battery (C).
In other words, 404 kilograms is 6,200 times the weight of a Battery (C), and the weight of a Battery (C) is 0.00016 times that amount.
(Alkaline)
It's about 7,000 times as heavy as a Tennis Ball.
In other words, the weight of a Tennis Ball is 0.000143 times 404 kilograms.
(ITF Standard; for Type 2 ball) 
