21363191 has 2 divisors, whose sum is σ = 21363192. Its totient is φ = 21363190.

The previous prime is 21363179. The next prime is 21363193. The reversal of 21363191 is 19136312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21363191 - 2¹⁰ = 21362167 is a prime.

Together with 21363193, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21363191.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21363193) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10681595 + 10681596.

It is an arithmetic number, because the mean of its divisors is an integer number (10681596).

Almost surely, 2^21363191 is an apocalyptic number.

21363191 is a deficient number, since it is larger than the sum of its proper divisors (1).

21363191 is an equidigital number, since it uses as much as digits as its factorization.

21363191 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 972, while the sum is 26.

The square root of 21363191 is about 4622.0332106120. The cubic root of 21363191 is about 277.4738378604.

The spelling of 21363191 in words is "twenty-one million, three hundred sixty-three thousand, one hundred ninety-one".