218320 has 20 divisors (see below), whose sum is σ = 507780. Its totient is φ = 87296.

The previous prime is 218287. The next prime is 218357. The reversal of 218320 is 23812.

It is a happy number.

218320 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 156816 + 61504 = 396^2 + 248^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a junction number, because it is equal to n+sod(n) for n = 218294 and 218303.

It is a congruent number.

It is an unprimeable number.

218320 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1285 + ... + 1444.

It is an arithmetic number, because the mean of its divisors is an integer number (25389).

2²¹⁸³²⁰ is an apocalyptic number.

218320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

218320 is an abundant number, since it is smaller than the sum of its proper divisors (289460).

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

218320 is a wasteful number, since it uses less digits than its factorization.

218320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2742 (or 2736 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 218320 is about 467.2472578839. The cubic root of 218320 is about 60.2140502814.

It can be divided in two parts, 2183 and 20, that multiplied together give a triangular number (43660 = T₂₉₅).

The spelling of 218320 in words is "two hundred eighteen thousand, three hundred twenty".