18309011920 has 40 divisors (see below), whose sum is σ = 43718958504. Its totient is φ = 7125668352.

The previous prime is 18309011911. The next prime is 18309011923. The reversal of 18309011920 is 2911090381.

It can be written as a sum of positive squares in 4 ways, for example, as 8234473536 + 10074538384 = 90744^2 + 100372^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18309011923) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3089779 + ... + 3095698.

Almost surely, 2^18309011920 is an apocalyptic number.

18309011920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18309011920 is an abundant number, since it is smaller than the sum of its proper divisors (25409946584).

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

18309011920 is a wasteful number, since it uses less digits than its factorization.

18309011920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6185527 (or 6185521 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 34.

The spelling of 18309011920 in words is "eighteen billion, three hundred nine million, eleven thousand, nine hundred twenty".