218389 has 2 divisors, whose sum is σ = 218390. Its totient is φ = 218388.

The previous prime is 218381. The next prime is 218401. The reversal of 218389 is 983812.

218389 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 184900 + 33489 = 430^2 + 183^2 .

It is a cyclic number.

It is not a de Polignac number, because 218389 - 2³ = 218381 is a prime.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

218389 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 218389.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (218381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109194 + 109195.

It is an arithmetic number, because the mean of its divisors is an integer number (109195).

2²¹⁸³⁸⁹ is an apocalyptic number.

It is an amenable number.

218389 is a deficient number, since it is larger than the sum of its proper divisors (1).

218389 is an equidigital number, since it uses as much as digits as its factorization.

218389 is an odious number, because the sum of its binary digits is odd.

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

The square root of 218389 is about 467.3210887602. The cubic root of 218389 is about 60.2203931601.

The spelling of 218389 in words is "two hundred eighteen thousand, three hundred eighty-nine".