21817852943023 has 2 divisors, whose sum is σ = 21817852943024. Its totient is φ = 21817852943022.

The previous prime is 21817852943021. The next prime is 21817852943063. The reversal of 21817852943023 is 32034925871812.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21817852943023 - 2¹ = 21817852943021 is a prime.

Together with 21817852943021, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21817852943021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10908926471511 + 10908926471512.

It is an arithmetic number, because the mean of its divisors is an integer number (10908926471512).

Almost surely, 2^{21817852943023} is an apocalyptic number.

21817852943023 is a deficient number, since it is larger than the sum of its proper divisors (1).

21817852943023 is an equidigital number, since it uses as much as digits as its factorization.

21817852943023 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5806080, while the sum is 55.

The spelling of 21817852943023 in words is "twenty-one trillion, eight hundred seventeen billion, eight hundred fifty-two million, nine hundred forty-three thousand, twenty-three".