218439 has 12 divisors (see below), whose sum is σ = 339976. Its totient is φ = 134352.

The previous prime is 218437. The next prime is 218447. The reversal of 218439 is 934812.

It is not a de Polignac number, because 218439 - 2¹ = 218437 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218437) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 817 + ... + 1050.

2²¹⁸⁴³⁹ is an apocalyptic number.

218439 is a deficient number, since it is larger than the sum of its proper divisors (121537).

218439 is a wasteful number, since it uses less digits than its factorization.

218439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1886 (or 1883 counting only the distinct ones).

The product of its digits is 1728, while the sum is 27.

The square root of 218439 is about 467.3745821073. The cubic root of 218439 is about 60.2249886142.

The spelling of 218439 in words is "two hundred eighteen thousand, four hundred thirty-nine".