218987 has 2 divisors, whose sum is σ = 218988. Its totient is φ = 218986.

The previous prime is 218971. The next prime is 218989. The reversal of 218987 is 789812.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 218987 - 2⁴ = 218971 is a prime.

Together with 218989, 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 not a weakly prime, because it can be changed into another prime (218989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109493 + 109494.

It is an arithmetic number, because the mean of its divisors is an integer number (109494).

2²¹⁸⁹⁸⁷ is an apocalyptic number.

218987 is a deficient number, since it is larger than the sum of its proper divisors (1).

218987 is an equidigital number, since it uses as much as digits as its factorization.

218987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8064, while the sum is 35.

The square root of 218987 is about 467.9604684159. The cubic root of 218987 is about 60.2753088922.

The spelling of 218987 in words is "two hundred eighteen thousand, nine hundred eighty-seven".