18887904 has 144 divisors (see below), whose sum is σ = 63842688. Its totient is φ = 5380992.

The previous prime is 18887861. The next prime is 18887923. The reversal of 18887904 is 40978881.

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

It is a self number, because there is not a number n which added to its sum of digits gives 18887904.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 54259 + ... + 54605.

It is an arithmetic number, because the mean of its divisors is an integer number (443352).

Almost surely, 2^18887904 is an apocalyptic number.

18887904 is a gapful number since it is divisible by the number (14) 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 18887904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31921344).

18887904 is an abundant number, since it is smaller than the sum of its proper divisors (44954784).

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

18887904 is an equidigital number, since it uses as much as digits as its factorization.

18887904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 379 (or 359 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 45.

The square root of 18887904 is about 4346.0216290304. The cubic root of 18887904 is about 266.3143625395.

It can be divided in two parts, 18887 and 904, that added together give a palindrome (19791).

The spelling of 18887904 in words is "eighteen million, eight hundred eighty-seven thousand, nine hundred four".