### Properties of the number 21067:

21067 is a cyclic number.21067 is the 2370

^{th}prime.

21067 has 17 antidivisors and 21066 totatives.

21067 = 10534

^{2}- 10533

^{2}is the difference of 2 nonnegative squares in 1 way.

21067 is the sum of 2 positive triangular numbers.

21067 is the difference of 2 positive pentagonal numbers in 1 way.

21067 = 15

^{2}+ 31

^{2}+ 141

^{2}is the sum of 3 positive squares.

21067

^{2}is the sum of 3 positive squares.

21067 is a proper divisor of 23

^{3511}- 1.

21067 is an emirp in (at least) the following bases: 5, 13, 21, 29, 37, 41, 51, 53, 55, 59, 61, 62, 65, 69, 71, 73, 82, 89, 93, and 95.

21067 is palindromic in (at least) the following bases: 52, 54, and -38.

21067 in base 17 = 44f4 and consists of only the digits '4' and 'f'.

21067 in base 37 = FEE and consists of only the digits 'E' and 'F'.

21067 in base 52 = 7f7 and consists of only the digits '7' and 'f'.

21067 in base 53 = 7QQ and consists of only the digits '7' and 'Q'.

21067 in base 54 = 7C7 and consists of only the digits '7' and 'C'.

### The number 21067 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.A023327: Numbers n such that n remains prime through 4 iterations of function f(x) = 9x + 10.

A023355: Numbers n such that n remains prime through 5 iterations of function f(x) = 9x + 10.

A046014: Discriminants of imaginary quadratic fields with class number 17 (negated).

A051334: Euclid-Mullin sequence (A000945) with initial value a(1)=8191 instead of a(1)=2.

A077345: a(n) is the n-th prime whose decimal expansion begins with the decimal expansion of n.

A142820: Primes congruent to 22 mod 61.

A174812: Primes of the form n^2+42.

A180452: Primes of the form floor(n^sqrt(pi)).

A261210: a(n) = gpf(1 + Product_{k=0..4} prime(n+k)), where gpf is greatest prime factor and prime(i) is the i-th prime.

A272421: Partial sums of the number of active (ON,black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 470", based on the 5-celled von Neumann neighborhood.

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