23
This number is a prime.
Just showing those entries submitted by 'Das': (Click here to show all)
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Kristen Eller ©2002 |
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The smallest prime that is both preceded and followed by a prime number of successive composites. [Beedassy]
23! is the least factorial in which the digits 0 through 9 appear at least once. [Das]
23 is the largest row of Pascal's triangle all of whose entries are square-free (or 1). [Beedassy]
The number of characters in the interjection : "Yeah! Hints on the primes" (a most fitting anagram for "The
Riemann Hypothesis" due to V. Rabin). [Beedassy]
The smallest prime p that divides the sum of the first p primes. [Beedassy]
There are exactly 23 prime-digit primes below one thousand,
and 23 is one of them (more precisely the nth,
where n is the (prime) sum of its digits). [Beedassy]
The smallest prime which when prefixed to the smallest
pandigital string forms another prime: 230123456789. [Beedassy]
The first prime whose complexity
is a prime smaller than itself (i.e., whose representation
involving only addition, multiplication, brackets and 1's
makes use of a smaller prime number of 1's):
{(1+1)*(1+1+1)+1}*(1+1+1)+1+1. [Beedassy]
The smallest prime p such that a prime is formed both from the ordered and the reverse concatenations of the first noncomposites up to p: 123571113171923 ; 231917131175321. [Beedassy]
The smallest home
prime for composite numbers. [Beedassy]
"PneumoVax 23" is the trade name for an
anti-Streptococcus pneumoniae germ vaccine
containing 23 of the most virulent and prevalent
pneumococcal antigen serotypes. [Beedassy]
The largest prime p for which there exists a p-digit number with exactly p divisors. Can you find this 23-digit number? [Beedassy]