218939 has 4 divisors (see below), whose sum is σ = 250224. Its totient is φ = 187656.

The previous prime is 218923. The next prime is 218941. The reversal of 218939 is 939812.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 218939 - 2⁴ = 218923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (218969) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15632 + ... + 15645.

It is an arithmetic number, because the mean of its divisors is an integer number (62556).

2²¹⁸⁹³⁹ is an apocalyptic number.

218939 is a deficient number, since it is larger than the sum of its proper divisors (31285).

218939 is an equidigital number, since it uses as much as digits as its factorization.

218939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31284.

The product of its digits is 3888, while the sum is 32.

The square root of 218939 is about 467.9091792218. The cubic root of 218939 is about 60.2709046334.

The spelling of 218939 in words is "two hundred eighteen thousand, nine hundred thirty-nine".