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.

Axel, a research prototype rover for exploring the Moon, Mars and other planets, is remotely driven over rocks as engineers from Jet Propulsion (JPL) and grad students from Caltech (California Institute of Technology) demonstrate its mobile over the steep and rocky grounds of the JPL Mars Yard on January 14, 2009 in Pasadena, California. The rover is capable of descending cliffs or into craters and returning by a cable tethered to its starting point. Development of the Axel rover is a point effort funded by NASA Exploration Systems Mission Directorate (ESMD) and lead by Principal Investigator Issa Newnas and Co-Investigator and Caltech professor of mechanical engineering bio engineering Joel Burdick. (Photo by David McNew/Getty Images)

Two of the first six “neighborhood electric vehicles” (NEV) to be leased by the U.S. Army are on display during an introductory ceremony at Fort Myer January 12, 2009 in Arlington, Virginia. The Army has leased 800 of the non-tactical NEVs with a goal of 4,000 vehicles by 2011. These NEVs are manufactured by the Global Electric Motorcars division of Chrysler Corporation. With a full eight-hour charge, the NEVs can traverse 30 miles at a top speed of 25-miles-per-hour. (Photo by Chip Somodevilla/Getty Images)

“Amphilophus citrinellus is a large cichlid fish endemic to the San Juan River and adjacent watersheds in Costa Rica and Nicaragua. In the aquarium trade A. citrinellus is often sold under the trade name of Midas cichlid. A. citrinellus are omnivorous and their diet consists of plant material, molluscs and smaller fish”. – Wikipedia

Photo: Two Midas Cichlid (lat: amphilophus citrinellus) fish are seen in an aquarium at Hellabrunn zoo on December 23, 2009 in Munich, Germany. (Photo by Alexandra Beier/Getty Images)

Maudy – Kalulushi, Zambia. Maudy was born in a hut in a small village close to Kalulushi, in Zambia. She grew up playing in the street with the other children in the village, who all attend the same school, where students ages 3 to 10 years old are in the same class. The village has no shops, restaurants or hotels, and just a few children are lucky enough to have toys. Maudy and her friends found a box full of sunglasses on the street, which quickly became their favorite toys. “Toy Stories” project. (Photo and caption by Gabriele Galimberti)

These heartwarming images capture the pure happiness of young children playing with a buffalo in the sweltering Indonesian heat on July 28, 2018. The children are all sons of the farmers who work on the rice farms in the West Java region of Indonesia. Amateur photographer Tamlikho Tam, 46 from Depok in West Java Indonesia snapped up the joyful moment because it shows what a typical childhood should be like without technology. (Photo by Tamlikho Tam/South West News Service)

Young people use single-use vaping products in London, Britain, 30 May 2023. The UK government has announced it is cracking down on retailers providing free vape samples to children. The government's new proposals include rules on fines for shops selling illicit vapes to children under 18-years-old. (Photo by Tolga Akmen/EPA)

A three month-old baby gorilla named Hasani sits in the grass March 11, 2009 at the San Francisco Zoo in San Francisco, California. The newborn gorilla was given the name Hasani. Hasani's father, a twenty seven year-old gorilla named Oscar Jonsey, picked between five color coded cantaloupes representing the five name finalists to come up with the newborn's name that was submitted by Amanda VerPloeg of Oskaloosa, Iowa. (Photo by Justin Sullivan/Getty Images)