Prime Curios!: 156

156
(another Prime Pages' Curiosity)

Curios:

Index
Keywords
Home
Random
Glossary
Previous
Next
Random

Curios Search: Participate:

Mail Editor
Submit Curio
Prime Puzzio
Test Number

The product of the number 156 multiplied by the first 4 primes equals 32760. Sigma(32760) = 131040, which makes it a multi-perfect number index 4. [Priebel]

156 = ((1) + (5) + (6)) * (prime(1)+prime(5)+prime(6)). Note that 156 is the smallest and only even number with this property. [Firoozbakht]

The smallest three digit number such that (2*4^n+1)/3 is prime. [Gallardo]