18564021823 has 2 divisors, whose sum is σ = 18564021824. Its totient is φ = 18564021822.

The previous prime is 18564021821. The next prime is 18564021829. The reversal of 18564021823 is 32812046581.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18564021823 - 2¹ = 18564021821 is a prime.

Together with 18564021821, 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 (18564021821) 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, 9282010911 + 9282010912.

It is an arithmetic number, because the mean of its divisors is an integer number (9282010912).

Almost surely, 2^18564021823 is an apocalyptic number.

18564021823 is a deficient number, since it is larger than the sum of its proper divisors (1).

18564021823 is an equidigital number, since it uses as much as digits as its factorization.

18564021823 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 92160, while the sum is 40.

The spelling of 18564021823 in words is "eighteen billion, five hundred sixty-four million, twenty-one thousand, eight hundred twenty-three".