18238385593 has 4 divisors (see below), whose sum is σ = 18683224308. Its totient is φ = 17793546880.

The previous prime is 18238385591. The next prime is 18238385603. The reversal of 18238385593 is 39558383281.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3609966889 + 14628418704 = 60083^2 + 120948^2 .

It is a cyclic number.

It is not a de Polignac number, because 18238385593 - 2¹ = 18238385591 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18238385591) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 222419296 + ... + 222419377.

It is an arithmetic number, because the mean of its divisors is an integer number (4670806077).

Almost surely, 2^18238385593 is an apocalyptic number.

It is an amenable number.

18238385593 is a deficient number, since it is larger than the sum of its proper divisors (444838715).

18238385593 is an equidigital number, since it uses as much as digits as its factorization.

18238385593 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 444838714.

The product of its digits is 6220800, while the sum is 55.

The spelling of 18238385593 in words is "eighteen billion, two hundred thirty-eight million, three hundred eighty-five thousand, five hundred ninety-three".