218304 has 42 divisors (see below), whose sum is σ = 627380. Its totient is φ = 72576.

The previous prime is 218287. The next prime is 218357. The reversal of 218304 is 403812.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nialpdrome in base 12.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 218304.

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 5 ways as a sum of consecutive naturals, for example, 387 + ... + 765.

2²¹⁸³⁰⁴ is an apocalyptic number.

218304 is a gapful number since it is divisible by the number (24) 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 218304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (313690).

218304 is an abundant number, since it is smaller than the sum of its proper divisors (409076).

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

218304 is a wasteful number, since it uses less digits than its factorization.

218304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 397 (or 384 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 218304 is about 467.2301360144. The cubic root of 218304 is about 60.2125792780.

The spelling of 218304 in words is "two hundred eighteen thousand, three hundred four".