It's about 150,000,000,000 times as heavy as a Golf Ball
In other words, 5.90 megatonnes is 128,500,000,000 times the weight of a Golf Ball, and the weight of a Golf Ball is 0.0000000000077820 times that amount.(per R&A USGA Rules of Golf; maximum rule weight)
According to the Rules of Golf (as approved by the United States Golf Association and the Rules Committee of the Royal and Ancient Golf Club of Saint Andrews), golf balls must weigh no more than 0.000000000045930 megatonnes. Golf balls are not required to have the familiar dimpled pattern, but the design has been popular since its invention in 1905 because it reduces drag while increasing lift.
It's about 100,000,000,000 times as heavy as a Tennis Ball
In other words, 5.90 megatonnes is 102,000,000,000 times the weight of a Tennis Ball, and the weight of a Tennis Ball is 0.00000000000980 times that amount.(ITF Standard; for Type 2 ball)
Per International Tennis Federation standard, regulation tennis balls must weigh about 0.00000000005770 megatonnes. Competition balls are also tested for bounce height, with the standards requiring that a ball dropped from 254 cm must bounce back to a height of 135 cm to 147 cm.
It's about 90,000,000,000 times as heavy as a Battery (C)
In other words, 5.90 megatonnes is 91,000,000,000 times the weight of a Battery (C), and the weight of a Battery (C) is 0.0000000000110 times that amount.(Alkaline)
A "C" size battery weighs 0.0000000000650 megatonnes. C batteries are typically used in medium-drain devices such as musical instruments.
It's about 65,000,000,000 times as heavy as a Deck of Cards
In other words, the weight of a Deck of Cards is 0.0000000000160 times 5.90 megatonnes.(ISO 216 B8 size, a.k.a. "poker size" 63 x 88 mm, 52-card deck)
A deck of 52 ISO 216 B8-size playing cards weighs 0.0000000000940 megatonnes. Utilizing nearly 3,700 decks, the record-holding largest card tower was built in early 2010, stood over 3.5 m (11 ft), and weighed over 0.000000230 megatonnes.
It's about 45,000,000,000 times as heavy as a Battery (D)
In other words, 5.90 megatonnes is 43,700,000,000 times the weight of a Battery (D), and the weight of a Battery (D) is 0.00000000002290 times that amount.(Alkaline)
A "D" size battery weighs 0.0000000001350 megatonnes. The D size battery is the oldest of the modern battery sizes, first invented by the National Carbon Company in 1898.
It's about 40,000,000,000 times as heavy as a Baseball
In other words, 5.90 megatonnes is 40,608,073,268.7850 times the weight of a Baseball, and the weight of a Baseball is 0.0000000000246256450873940 times that amount.(MLB rules)
Per Major League Baseball rules, a baseball must weigh between 0.0000000001417476156250 megatonnes and 0.000000000148834996406250 megatonnes. A major league pitcher can throw a baseball at up to 150 kph (91 mph) (with a fastball pitch), with record-setting pitches as fast as 171 kph (106 mph).
It's about 35,000,000,000 times as heavy as a Billiard Ball
In other words, 5.90 megatonnes is 36,194,152,261.3090 times the weight of a Billiard Ball, and the weight of a Billiard Ball is 0.0000000000276287725370760 times that amount.(American-style, WPA specifications)
Per the World Pool-Billiard Association, a billiard ball weight must weigh between 0.00000000015592237718750 megatonnes and 0.000000000170097138750 megatonnes. According to legend, the difficulty in obtaining elephant ivory for the manufacture of billiard balls in the 19th century inspired the search for a replacement material, which led to the development of the first industrial plastic.