241543903 (a.k.a “Heads in Freezers”) is a numerical keyword associated with a photo meme that involves people taking pictures with their heads in the freezer & sharing them online. By tagging a series of image files with a cryptic number, a high level of search engine optimization can be easily achieved. As a result, typing “241543903” into image search engines like Google Images successfully yields pages after pages of pictures showing people’s heads in freezers.
In 2009, David Horvitz started the “Heads in Freezers” meme. Participants took photos of their heads in freezers, tagged them with “241543903” and uploaded them to social media sites like Tumblr.

The tempestuous stellar nursery called the Carina Nebula, located 7,500 light-years away from Earth in the southern constellation Carina. (Photo by Reuters/NASA)

“Philippe Halsman (2 May 1906 Riga, Russian Empire – 25 June 1979 New York City) was a Latvian-born American portrait photographer. Many celebrities photographed by Halsman include Alfred Hitchcock, Judy Garland, Winston Churchill, Marilyn Monroe, Dorothy Dandridge, and Pablo Picasso. Many of those photographs appeared on the cover of Life. In such photos, he utilizes a variety of his rules of photography. For example, in one of his photos of Winston Churchill, the omission of his face makes Halsman's photo even more powerful at making Churchill more human”. – Wikipedia

Photo: Marilyn Monroe, “Jumpology”, 1959. Photo by Philippe Halsman

BAZ-69092-012 special wheeled chassis. Exhibition of military vehicles at Bronnitsy test range (a town in Moscow Oblast, Russia, located 54.5 kilometers (33.9 mi) southeast of central Moscow). Juny 10, 2011. (Photo by Vitaly Kuzmin)

A three wheeled “cabin” scooter manufactured by German aircraft engineers Messerschmitt & Co at factories in Regensburg. (Photo by Hans Enzwieser/BIPs/Getty Images). 1955

Tsar Alexander II (1818–1881) known as “The Liberator” lying in state. He was mortally wounded by an assassination attack in St Petersburg. (Photo by Hulton Archive/Getty Images). March 1881

The attendants of the Sumptha Raja, Agra Durbar. (Photo by Hulton Archive/Getty Images). 1873

Clutching a large paper bag and shading his eyes as he peers ahead, comic actor of the silent screen, Buster Keaton (1885–1966) arriving at Paris airport. (Photo by Keystone/Getty Images). 1st August 1947