218838 has 8 divisors (see below), whose sum is σ = 437688. Its totient is φ = 72944.

The previous prime is 218833. The next prime is 218839. The reversal of 218838 is 838812.

It is a sphenic number, since it is the product of 3 distinct primes.

218838 is an admirable number.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 218838.

It is not an unprimeable number, because it can be changed into a prime (218833) by changing a digit.

218838 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18231 + ... + 18242.

It is an arithmetic number, because the mean of its divisors is an integer number (54711).

2²¹⁸⁸³⁸ is an apocalyptic number.

218838 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

218838 is a wasteful number, since it uses less digits than its factorization.

218838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36478.

The product of its digits is 3072, while the sum is 30.

The square root of 218838 is about 467.8012398444. The cubic root of 218838 is about 60.2616352362.

The spelling of 218838 in words is "two hundred eighteen thousand, eight hundred thirty-eight".