218868687 has 6 divisors (see below), whose sum is σ = 316143672. Its totient is φ = 145912452.

The previous prime is 218868679. The next prime is 218868721. The reversal of 218868687 is 786868812.

It is not a de Polignac number, because 218868687 - 2³ = 218868679 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218868677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12159363 + ... + 12159380.

It is an arithmetic number, because the mean of its divisors is an integer number (52690612).

Almost surely, 2^218868687 is an apocalyptic number.

218868687 is a deficient number, since it is larger than the sum of its proper divisors (97274985).

218868687 is a wasteful number, since it uses less digits than its factorization.

218868687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24318749 (or 24318746 counting only the distinct ones).

The product of its digits is 2064384, while the sum is 54.

The square root of 218868687 is about 14794.2112665732. The cubic root of 218868687 is about 602.6445187433.

The spelling of 218868687 in words is "two hundred eighteen million, eight hundred sixty-eight thousand, six hundred eighty-seven".