18385280720 has 20 divisors (see below), whose sum is σ = 42745777860. Its totient is φ = 7354112256.

The previous prime is 18385280699. The next prime is 18385280747. The reversal of 18385280720 is 2708258381.

It can be written as a sum of positive squares in 2 ways, for example, as 14088740416 + 4296540304 = 118696^2 + 65548^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a hoax number, since the sum of its digits (44) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 114907925 + ... + 114908084.

It is an arithmetic number, because the mean of its divisors is an integer number (2137288893).

Almost surely, 2^18385280720 is an apocalyptic number.

18385280720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18385280720 is an abundant number, since it is smaller than the sum of its proper divisors (24360497140).

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

18385280720 is a wasteful number, since it uses less digits than its factorization.

18385280720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 229816022 (or 229816016 counting only the distinct ones).

The product of its (nonzero) digits is 215040, while the sum is 44.

The spelling of 18385280720 in words is "eighteen billion, three hundred eighty-five million, two hundred eighty thousand, seven hundred twenty".