19

This number is a prime.

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

+ The smallest prime that yields another if its sum of digits is sandwiched between its digits. [Silva]

+ The smallest prime formed from distinct non-prime digits. [Silva]

+ The first prime p such that p^2 is the reversal of a prime (163). [Silva]

+ The sum of all single-digit semiprimes. Insert two 0's between its digits and you will have the sum of the cubes of those semiprimes. [Silva]

+ The smallest prime that is the sum of first p-th primes. [Silva]

+ There are 19 ways of expressing the smallest three-digit prime as the sum of three distinct two-digit primes. [Silva]

+ The smallest prime whose reversal is not prime. [Silva]

+ 19 is the smallest prime containing a composite digit. [Silva]

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