Prime Curios!: 101111

101111
(another Prime Pages' Curiosity)

Curios:

Index
Keywords
Home
Random
Glossary
The book!
Previous
Next
Random

Curios Search:
Participate:

Mail Editor
Submit Curio
Prime Puzzio
Test Number

101111 is prime when read as a base-two number. This is the last of only four primes in the first 10,000 that are both a prime when read as a base-two and a base-ten number. [Connolly]

The smallest prime concatenated from the binary representations of a twin prime pair. 101 (base 2) = 5 (base 10) concatenated with 111 (base 2) = 7 (base 10), with (5,7) the second twin prime pair. [Post]

(There is one curio for this number that has not yet been approved by an editor.)