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.

Felix Guirola, 52, rides a homemade bike with an advertising banner in Havana, Cuba, July 20, 2016. The handyman, who loves heights, provides advertising space for companies on homemade bikes that tower up to 7.5 meters (24.61 ft). He rides them around Havana in an ingenious way of getting around strict marketing regulations in the Communist-ruled island. (Photo by Alexandre Meneghini/Reuters)

Touching and dramatic portraits and landscape shots have won prizes at Australia's prestigious photography prize. Photo: Winner of the NSW (New South Wales) prize: Peter Solness said: “I wanted to re-imagine the lost waterways, so I got my light-painting tools to work. In this image, water is being released from the top of the historic Centennial Park No. 2 Reservoir, which was built in 1925 and holds 90 megalitres of water. After 89 years of incarceration these waters now run free!”. (Photo by Peter Solness/Head On)

3D interactive artist Joe Hill poses with one of his works as part of the VisitBritain tourism campaign at Circular Quay on September 6, 2011 in Sydney, Australia. (Photo by Mark Metcalfe/Getty Images)

Katy Perry attends the European premiere of Katy Perry: «Part Of Me 3D» at Empire Leicester Square on July 3, 2012 in London, England. (Photo by Mike Marsland)

Street artist Juandres Vera puts the finishing touches to a giant 3d pavement mural of The Beatles on September 23, 2011 in Liverpool, England. The giant 24m long by 6m wide work, entitled “XXL Liverpool” has been commissioned to celebrate the dual 50th anniversary of The Beatles first gig at The Cavern Club and meeting their manager Brian Epstein. The Beatles drawing kicks off The James Carling International Pavement Art Competition which starts on Sunday and will feature more than 50 of the world's best pavement artists (Photo by Christopher Furlong/Getty Images)

French engineer and professional violinist Laurent Bernadac poses with the “3Dvarius”, a 3D printed violin made of transparent resin, during an interview with Reuters in Paris, France, September 11, 2015. (Photo by Christian Hartmann/Reuters)

Monika Horčicová is a Czech sculptor/installation artist who constructs human skeletons with 3-D printing in a very surreal juxtaposition. Many of her structures presents itself through a repetitive cycling pattern as well as experimental evolved mutations.