18005387680 has 96 divisors (see below), whose sum is σ = 48883685760. Its totient is φ = 6139100160.

The previous prime is 18005387669. The next prime is 18005387683. The reversal of 18005387680 is 8678350081.

It is a self number, because there is not a number n which added to its sum of digits gives 18005387680.

It is not an unprimeable number, because it can be changed into a prime (18005387683) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 158311 + ... + 247129.

It is an arithmetic number, because the mean of its divisors is an integer number (509205060).

Almost surely, 2^18005387680 is an apocalyptic number.

18005387680 is a gapful number since it is divisible by the number (10) 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 18005387680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24441842880).

18005387680 is an abundant number, since it is smaller than the sum of its proper divisors (30878298080).

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

18005387680 is a wasteful number, since it uses less digits than its factorization.

18005387680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89022 (or 89014 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 46.

The spelling of 18005387680 in words is "eighteen billion, five million, three hundred eighty-seven thousand, six hundred eighty".