1223

This number is a prime.

+ The smallest prime (emirp) formed from a Pythagorean quadruple (1-2-2-3). It is also a left-truncatable prime. [Loungrides]

+ The smallest prime concatenating the sequence of the number of divisors of n, in this case for n = 1, 2, 3, 4. [Post]

+ In the penultimate Bible verse (Revelation 22:20), Lord Jesus has an isopsephia value of 1223. [Slattery]

+ Prime formed from concatenation of the first four terms of the Golomb sequence.

+ The smallest prime (emirp) obtained by concatenating an integer with the product and sum of its own digits. [Loungrides]

+ The larger of only two non-titanic primes p, that is the product of a repunit number and all truncations of itself plus two, i.e., 111*11*1+2. Note that the other such prime, 11*1+2, is also emirp. [Loungrides]

+ Smallest prime formed by concatenating a number with its ordered distinct prime factors. (For 12, they are 2 and 3.) [Sariyar]

(There are 10 curios for this number that have not yet been approved by an editor.)

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