It's about 30,000 times as heavy as a Battery (D)
In other words, 3,750,000 grams is 27,800 times the weight of a Battery (D), and the weight of a Battery (D) is 0.0000360 times that amount.(Alkaline)
A "D" size battery weighs 135 g. The D size battery is the oldest of the modern battery sizes, first invented by the National Carbon Company in 1898.
It's about one-thirty-thousandth as heavy as The CN Tower
In other words, 3,750,000 grams is 0.0000318040 times the weight of The CN Tower, and the weight of The CN Tower is 31,443 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 117,910,000,000 grams. 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.
It's about 40,000 times as heavy as a Deck of Cards
In other words, the weight of a Deck of Cards is 0.0000250 times 3,750,000 grams.(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 94 g. 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 230,000 grams.
It's about one-fifty-five-thousandth as heavy as The Sears Tower
In other words, 3,750,000 grams is 0.000018580 times the weight of The Sears Tower, and the weight of The Sears Tower is 53,820 times that amount.(officially "Willis Tower" as of 2009) (Chicago, Illinois)
The Willis Tower weighs approximately 201,800,000,000 grams. 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 60,000 times as heavy as a Battery (C)
In other words, 3,750,000 grams is 58,000 times the weight of a Battery (C), and the weight of a Battery (C) is 0.0000170 times that amount.(Alkaline)
A "C" size battery weighs 65 g. C batteries are typically used in medium-drain devices such as musical instruments.
It's about 65,000 times as heavy as a Tennis Ball
In other words, the weight of a Tennis Ball is 0.00001540 times 3,750,000 grams.(ITF Standard; for Type 2 ball)
Per International Tennis Federation standard, regulation tennis balls must weigh about 56.0 g to 59.4 g. 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 80,000 times as heavy as a Golf Ball
In other words, 3,750,000 grams is 81,650 times the weight of a Golf Ball, and the weight of a Golf Ball is 0.000012250 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 45.93 g. 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.