218904 has 32 divisors (see below), whose sum is σ = 625920. Its totient is φ = 62496.

The previous prime is 218887. The next prime is 218923. The reversal of 218904 is 409812.

218904 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×218904² = 95837922432, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 484 + ... + 819.

It is an arithmetic number, because the mean of its divisors is an integer number (19560).

2²¹⁸⁹⁰⁴ is an apocalyptic number.

218904 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

218904 is an abundant number, since it is smaller than the sum of its proper divisors (407016).

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

218904 is a wasteful number, since it uses less digits than its factorization.

218904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1319 (or 1315 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 218904 is about 467.8717773066. The cubic root of 218904 is about 60.2676927889.

The spelling of 218904 in words is "two hundred eighteen thousand, nine hundred four".