218138 has 8 divisors (see below), whose sum is σ = 338580. Its totient is φ = 105280.

The previous prime is 218137. The next prime is 218143. The reversal of 218138 is 831812.

It can be written as a sum of positive squares in 2 ways, for example, as 218089 + 49 = 467^2 + 7^2 .

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

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 218138.

It is not an unprimeable number, because it can be changed into a prime (218131) 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, 1823 + ... + 1938.

2²¹⁸¹³⁸ is an apocalyptic number.

218138 is a deficient number, since it is larger than the sum of its proper divisors (120442).

218138 is a wasteful number, since it uses less digits than its factorization.

218138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3792.

The product of its digits is 384, while the sum is 23.

The square root of 218138 is about 467.0524595803. The cubic root of 218138 is about 60.1973133755.

The spelling of 218138 in words is "two hundred eighteen thousand, one hundred thirty-eight".