18909504 has 112 divisors (see below), whose sum is σ = 57546240. Its totient is φ = 6082560.

The previous prime is 18909497. The next prime is 18909509. The reversal of 18909504 is 40590981.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18909509) 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, 53392 + ... + 53744.

Almost surely, 2^18909504 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18909504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28773120).

18909504 is an abundant number, since it is smaller than the sum of its proper divisors (38636736).

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

18909504 is a wasteful number, since it uses less digits than its factorization.

18909504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 405 (or 389 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The square root of 18909504 is about 4348.5059503236. The cubic root of 18909504 is about 266.4158419278.

The spelling of 18909504 in words is "eighteen million, nine hundred nine thousand, five hundred four".