Curios:
Curios Search:
Participate:
|
The number of 8-digit primes (on a calculator) that remain prime if
viewed upside down, in a mirror, or upside down in a mirror. [Russo]
Mersenne wrongly thought 2^257-1 is prime. In fact, 52 is the smallest base b for which (b^257-1)/b-1 is actually prime.
52! + 52 + 1 is prime. Note that 52 is the (5-2)rd untouchable number. [Mojdeh]
The element with atomic number 52 (Tellurium) is the only one whose atomic weight's integer part is a Mersenne prime. [Wu]
52 = (5!*2!). [Firoozbakht]
|