11

This number is a prime.

Just showing those entries submitted by 'Russo': (Click here to show all)

The smallest two-digit additive prime (a prime whose sum of digits is prime). [Russo]

The smallest prime p such that 2^p - 1 is composite. [Russo]

The smallest multidigit Lucasian prime: p is congruent to 3 (mod 4) with 2p+1 prime. [Russo]

The smallest prime p such that 6*p-1 is composite. [Russo]

The smallest palindromic prime p such that 2^p-1 has at most 2 prime factors. [Russo]

The smallest strong prime. A strong prime is a prime that is greater than the arithmetic mean of the nearest prime above and below. [Russo]