It's about one-one-hundred-fifty-thousandth as tall as a Mauna Loa
In other words, 2.10 inches is 0.000005818 times the height of a Mauna Loa, and the height of a Mauna Loa is 171,900 times that amount.(Hawaii) (Hawaiian island volcano) (total height from seafloor)
Mauna Loa, one of the five volcanoes which forms the island of Hawaii and the tallest mountain in total height in the world, rises to 362,200 inches above the seafloor. The peak of Loa is home to the approximately 6,000 sq. m (0.6 ha) Lake Waiau, one of the highest altitude lakes in the United States outside of Colorado.
It's about one-two-hundred-thousandth as deep as The Challenger Deep (Marianas Trench)
In other words, 2.10 inches is 0.0000048927 times the depth of The Challenger Deep (Marianas Trench), and the depth of The Challenger Deep (Marianas Trench) is 204,390 times that amount.(near Marianas Islands, a.k.a. Ladrones Islands, northwestern Pacific Ocean) (depth below sea level)
The Challenger Deep, at the southern end of the Marianas Trench, reaches a depth of 429,210 inches below sea level. The first manned expedition to the bottom of Challenger Deep took 4 hours and 48 minutes in 1960. This was the only manned descent to the floor of the Trench until 2012, when director James Cameron made the trip; several other descents have been made since then.
It's about one-two-hundred-thousandth as tall as Maxwell Montes
In other words, 2.10 inches is 0.0000048 times the height of Maxwell Montes, and the height of Maxwell Montes is 210,000 times that amount.(Ishtar Terra, Venus)
Maxwell Montes rises to a total height of 430,000 inches. Since Venus does not seem to have the kind of tectonic activity which gives rise to mountains on Earth, the origin of the Venusian mountain remains the subject of some dispute.
It's about one-five-hundred-thousandth as tall as Olympus Mons
In other words, 2.10 inches is 0.0000020 times the height of Olympus Mons, and the height of Olympus Mons is 500,000 times that amount.(a.k.a. Mount Olympus) (Mars)
The tallest mountain in the solar system, Olympus Mons rises to approximately 1,100,000 inches. The mountain has been known to astronomers since the nineteenth century because it is tall enough to rise above Mars' frequent dust storms.
It's about 0.0000006 times as long as The Panama Canal
In other words, 2.10 inches is 0.00000061 times the length of The Panama Canal, and the length of The Panama Canal is 1,600,000 times that amount.(Canal de Panamá) (Panama)
Connecting the Atlantic and Pacific Oceans across the Isthmus of Panama, the Canal measures 3,500,000 inches in length. Ships passing through the Canal are raised (and then lowered) 1,000 inches above sea level through the lock-and-dam system.
It's about 0.0000005 times as wide as The English Channel
In other words, 2.10 inches is 0.000000499 times the width of The English Channel, and the width of The English Channel is 2,000,000 times that amount.(average width between Isle of Ushant and The Walde Lighthouse) (La Manche, Ärmelkanal, Mor Breizh, Mor Bretannek) (a.k.a. The Channel)
The English Channel measures between 4,210,000 inches, narrowing as it flows northeast. The world speed record for a Channel crossing by swimmer was set by Australian Trent Grimsey in 2012, with a time of 6 hours, 55 minutes.
It's about 0.0000005 times as long as The 405
In other words, 2.10 inches is 0.0000004577 times the length of The 405, and the length of The 405 is 2,184,800 times that amount.(a.k.a. I-405, Interstate 405, San DIego Freeway) (Southern California)
Running from Irvine to San Fernando, The 405 runs a total of 4,588,200 inches. The 405 is the most heavily-trafficed freeway in the United States, with an average speed as low as 8 kph during rush hours.