218989 has 2 divisors, whose sum is σ = 218990. Its totient is φ = 218988.

The previous prime is 218987. The next prime is 218993. The reversal of 218989 is 989812.

218989 is nontrivially palindromic in base 15.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 218089 + 900 = 467^2 + 30^2 .

It is a cyclic number.

It is not a de Polignac number, because 218989 - 2¹ = 218987 is a prime.

Together with 218987, it forms a pair of twin primes.

It is a Chen prime.

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

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (218987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109494 + 109495.

It is an arithmetic number, because the mean of its divisors is an integer number (109495).

2²¹⁸⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

218989 is a deficient number, since it is larger than the sum of its proper divisors (1).

218989 is an equidigital number, since it uses as much as digits as its factorization.

218989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 37.

The square root of 218989 is about 467.9626053436. The cubic root of 218989 is about 60.2754923890.

It can be divided in two parts, 2189 and 89, that added together give a triangular number (2278 = T₆₇).

The spelling of 218989 in words is "two hundred eighteen thousand, nine hundred eighty-nine".