1729: the number connecting Futurama and Srinivasa Ramanujan.
A taxi, a hospital visit and a "dull" number that turned out to be the smallest expressible as the sum of two cubes in two ways — and then kept turning up in a cartoon set a thousand years from now.
Varchas KoushikFounder · Storyteller & Learning Experience Designer
Do you believe that a single number can connect the genius of Srinivasa Ramanujan to a futuristic animated TV series like Futurama? Well, the number 1729 does exactly that — and it's a story worth telling.
Why 1729 matters
The number 1729, known as the Ramanujan–Hardy number, has an incredible backstory. When G.H. Hardy, a renowned mathematician, visited Ramanujan in hospital, he remarked that the taxi he had arrived in was numbered 1729. Hardy thought it was a "dull number", but Ramanujan corrected him with one of the most elegant observations in mathematics:
It's the smallest number expressible as the sum of two positive cubes in two different ways.
1729 = 1³ + 12³ = 9³ + 10³. And just like that, 1729 became a mathematical marvel, immortalised as the taxicab number.
The Futurama connection
The creators of Futurama, known for embedding clever mathematical references into their episodes, couldn't resist using 1729. It pops up in multiple episodes — as a starship registry number in one, as a universe number in another.
But they didn't stop there. In a nod to Ramanujan's genius, they referenced another taxicab-related number, 87,539,319, which is the smallest number expressible as the sum of cubes in three distinct ways. Perfect for a taxicab in a futuristic world, don't you think?
What makes 1729 special beyond Futurama?
- Harshad number: the sum of its digits (1 + 7 + 2 + 9 = 19) divides it perfectly.
- Linked to e: at the 1729th decimal place of the irrational number e, we find the first occurrence of all ten digits consecutively.
- Third Carmichael number: a rare class of pseudoprime numbers.
- Sphenic number: divisible by exactly three distinct primes.
Why we made this video
We believe in making math accessible, fun and engaging. Numbers like 1729 aren't just for textbooks — they're bridges connecting history, creativity and even pop culture. That's why we created a short, visual video exploring how math and storytelling intersect.
Numbers like 1729 remind us that math is more than formulas — it's about curiosity, discovery and the stories they tell. Share this with someone who loves math, sci-fi, or stories that make learning exciting.
First published in the All Things Classroom newsletter
Written by
Varchas Koushik
Founder · Storyteller & Learning Experience Designer
Founder of All Things Classroom. 10,000+ hours facilitating sessions with students across age groups and geographies; writes about game-based learning, story-driven teaching and what's possible when a lesson is designed like an experience instead of a script.
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