4357

This number is a prime.

The last known prime number in the Euclid-Mullin sequence. [Poo Sung]

Smallest prime (after the obvious 43) from the concatenated digits of the limit of the product of a modified Zeta function. The next such prime is 43575707677264559. [Post]

The smallest Honaker prime that has triangular prime index. [Bajpai]

The smallest Honaker prime that can be expressed as the sum of the squares of two distinct triangular numbers, i.e., (1^2 + 66^2). Curiously, 66 is a palindromic triangular number having palindromic index. [Bajpai]