Curious Incident: Prime Suspects

Curiouser and Curiouser

Is your name a Prime Number? This week we were lucky enough to revisit Curious Incident of the Dog in the Night Time which is still in fabulous shape and regularly selling out at the Gielgud Theatre in Shaftesbury Avenue. Our Curious post will be online soon, and while we’re playing detective, here’s a little bit of fun inspired by the show:


On your visit to the show, you’ll find that prime number seats in the auditorium are marked out and contain a card which helps you work out whether your name is a prime number. Those lucky audience members who find out that they ARE a prime can collect prize in the foyer. So we thought we’d play along online just for fun using a hand cipher calculator!


A cipher is just a way of encrypting code. If you know your Bletchley Park back-story then you’ll know that codebreakers like Alan Turing were fundamental to British successes during WWII. In Curious Incident, Christopher is a gifted mathematician and it’s pretty certain he would have made a great code breaker himself. We’re going to use a very simple cipher to work out whether your name is a prime number.

ABC Cipher
ABC Cipher – use this to change your name into code


Life’s too short to do the coding yourself. We’ve found a shortcut – just type in your name and this nifty little cipher from Rumkin will covert your name into a series of numbers. e.g. if your name is Doctor Watson then your numbers are 4-15-3-20-18 23-1-20-19-15-14. Add them up and you get a number, in this case = 157.

You still have to do a little maths yourself but, once you’ve added up the sequence of numbers you’ll be left with a number which you can check against our list of primes in the grid below (e.g. Doctor Watson is 157):

See if your name is a Prime Number (the squares in grey are all primes)
See if your name is a Prime Number (the squares in grey are all primes)

If your name IS a prime, then Christopher Boone will definitely want to see you in the audience – and so will the team at the Gielgud Theatre! You can buy tickets for The Curious Incident of the Dog in the Night-Time at the Gielgud Theatre – and don’t forget to take some ID so you can prove your number is a prime and claim a prize at the interval.

If your name is a Prime Number, you’re in good company: Others include Terry Pratchett, Sherlock Holmes, Hermione Granger and Ron Weasley!

If you have a mind like Christopher Boone, you’ll have no trouble solving our Theatre Brainteasers!