JAMES GRIME: OK, so 42 is maybe not such a special number in mathematics, but a very special number in nerd culture. PHIL MORIARTY: Good. Good, good, good. Did you want to do something with 42? JAMES...
LAURENCE EAVES: The number today I'd like to talk to you about is 69. And it turns out to be an important number for this little pocket calculator. Well, in order to explain this, I need to...
BRADY HARAN: We did a video. I'd done it some time ago about Mersenne primes. And offhandedly, just off the cuff, I said that 1 wasn't a prime. Now, if I'm honest, we...