18388123536 has 40 divisors (see below), whose sum is σ = 49567988160. Its totient is φ = 5862879616.

The previous prime is 18388123511. The next prime is 18388123547. The reversal of 18388123536 is 63532188381.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8326851 + ... + 8329058.

It is an arithmetic number, because the mean of its divisors is an integer number (1239199704).

Almost surely, 2^18388123536 is an apocalyptic number.

18388123536 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

18388123536 is an abundant number, since it is smaller than the sum of its proper divisors (31179864624).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18388123536 is a wasteful number, since it uses less digits than its factorization.

18388123536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16655943 (or 16655937 counting only the distinct ones).

The product of its digits is 829440, while the sum is 48.

The spelling of 18388123536 in words is "eighteen billion, three hundred eighty-eight million, one hundred twenty-three thousand, five hundred thirty-six".