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.

Two girls dressed up for a night out in Newcastle, United Kingdom on November 01, 2020 – just hours after Boris Johnson's announcement. Johnson says the new measures will begin on Thursday and last until second of December. (Photo by North News and Pictures/The Sun)

Gentoo penguins watching Christmas films at the Sea Life London aquarium on November 30, 2020. The attraction has installed two TVs, showing festive films, outside the penguin enclosure to prepare them for the stimulation of guests returning on Wednesday after the UK’s lockdown is lifted. (Photo by Yui Mok/PA Images via Getty Images)

People protest getting evicted from land designated for a Petrobras refinery, at a settlement coined the “First of May Refugee Camp”, referring to the date people moved here and set up tents and shacks to live in during the new coronavirus pandemic in Itaguai, Rio de Janeiro state, Brazil, Thursday, July 1, 2021. (Photo by Silvia Izquierdo/AP Photo)

Commuters wear protective face masks as they walk through a subway station, in Sao Paulo, Brazil, Wednesday, December 1, 2021, amid the COVID-19 pandemic. Brazil joined the widening circle of countries to report cases of the omicron variant. (Photo by Andre Penner/AP Photo)

Raining on their New Year's Eve parade. Revellers in Leeds, United Kingdom get ready ready for the new year on December 31, 2022. (Photo by Nb press ltd)

A model has her hair sprayed backstage at the Ukrainian Fashion Week in Kyiv, Ukraine on August 31, 2020. (Photo by Gleb Garanich/Reuters)

Yanira Villarreal, left, Ayde Choque, center, and Milenda Limachi, wearings masks amid the COVID-19 pandemic and dressed as a “Cholita” pose for a photo with their skateboards during a youth talent show in La Paz, Bolivia, Wednesday, September 30, 2020. Young women called “Skates Imillas”, using the Aymara word for girl Imilla, use traditional Indigenous clothing as a statement of pride of their Indigenous culture while playing riding their skateboards. (Photo by Juan Karita/AP Photo)