218986 has 8 divisors (see below), whose sum is σ = 330624. Its totient is φ = 108780.

The previous prime is 218971. The next prime is 218987. The reversal of 218986 is 689812.

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

It is not an unprimeable number, because it can be changed into a prime (218987) by changing a digit.

218986 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, 201 + ... + 691.

It is an arithmetic number, because the mean of its divisors is an integer number (41328).

2²¹⁸⁹⁸⁶ is an apocalyptic number.

218986 is a deficient number, since it is larger than the sum of its proper divisors (111638).

218986 is a wasteful number, since it uses less digits than its factorization.

218986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 716.

The product of its digits is 6912, while the sum is 34.

The square root of 218986 is about 467.9593999483. The cubic root of 218986 is about 60.2752171433.

It can be divided in two parts, 21898 and 6, that added together give a square (21904 = 148²).

The spelling of 218986 in words is "two hundred eighteen thousand, nine hundred eighty-six".