218938 has 4 divisors (see below), whose sum is σ = 328410. Its totient is φ = 109468.

The previous prime is 218923. The next prime is 218941. The reversal of 218938 is 839812.

218938 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in only one way, i.e., 149769 + 69169 = 387^2 + 263^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable 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 as a sum of consecutive naturals, namely, 54733 + ... + 54736.

2²¹⁸⁹³⁸ is an apocalyptic number.

218938 is a deficient number, since it is larger than the sum of its proper divisors (109472).

218938 is a wasteful number, since it uses less digits than its factorization.

218938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109471.

The product of its digits is 3456, while the sum is 31.

The square root of 218938 is about 467.9081106371. The cubic root of 218938 is about 60.2708128712.

It can be divided in two parts, 218 and 938, that added together give a square (1156 = 34²).

The spelling of 218938 in words is "two hundred eighteen thousand, nine hundred thirty-eight".