18138733872 has 80 divisors (see below), whose sum is σ = 53766058752. Its totient is φ = 5161824000.

The previous prime is 18138733871. The next prime is 18138733889. The reversal of 18138733872 is 27833783181.

It is a super-2 number, since 2×18138733872² (a number of 21 digits) contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (18138733871) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23203 + ... + 191874.

Almost surely, 2^18138733872 is an apocalyptic number.

18138733872 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18138733872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26883029376).

18138733872 is an abundant number, since it is smaller than the sum of its proper divisors (35627324880).

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

18138733872 is a wasteful number, since it uses less digits than its factorization.

18138733872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215346 (or 215340 counting only the distinct ones).

The product of its digits is 1354752, while the sum is 51.

The spelling of 18138733872 in words is "eighteen billion, one hundred thirty-eight million, seven hundred thirty-three thousand, eight hundred seventy-two".