18904320 has 144 divisors (see below), whose sum is σ = 67206720. Its totient is φ = 5031936.

The previous prime is 18904313. The next prime is 18904349. The reversal of 18904320 is 2340981.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34287 + ... + 34833.

Almost surely, 2^18904320 is an apocalyptic number.

18904320 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 18904320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33603360).

18904320 is an abundant number, since it is smaller than the sum of its proper divisors (48302400).

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

18904320 is an equidigital number, since it uses as much as digits as its factorization.

18904320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 577 (or 557 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 18904320 is about 4347.9098426715. The cubic root of 18904320 is about 266.3914939253.

The spelling of 18904320 in words is "eighteen million, nine hundred four thousand, three hundred twenty".