18564021813 has 8 divisors (see below), whose sum is σ = 24759033376. Its totient is φ = 12372512400.

The previous prime is 18564021799. The next prime is 18564021821. The reversal of 18564021813 is 31812046581.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18564021813 - 2⁴ = 18564021797 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18564021823) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 863143 + ... + 884388.

It is an arithmetic number, because the mean of its divisors is an integer number (3094879172).

Almost surely, 2^18564021813 is an apocalyptic number.

It is an amenable number.

18564021813 is a deficient number, since it is larger than the sum of its proper divisors (6195011563).

18564021813 is a wasteful number, since it uses less digits than its factorization.

18564021813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1751075.

The product of its (nonzero) digits is 46080, while the sum is 39.

The spelling of 18564021813 in words is "eighteen billion, five hundred sixty-four million, twenty-one thousand, eight hundred thirteen".