218785985 has 8 divisors (see below), whose sum is σ = 286410816. Its totient is φ = 159117040.

The previous prime is 218785981. The next prime is 218785991. The reversal of 218785985 is 589587812.

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

It is not a de Polignac number, because 218785985 - 2² = 218785981 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (218785981) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 1988909 + ... + 1989018.

It is an arithmetic number, because the mean of its divisors is an integer number (35801352).

Almost surely, 2^218785985 is an apocalyptic number.

It is an amenable number.

218785985 is a deficient number, since it is larger than the sum of its proper divisors (67624831).

218785985 is a wasteful number, since it uses less digits than its factorization.

218785985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3977943.

The product of its digits is 1612800, while the sum is 53.

The square root of 218785985 is about 14791.4159227574. The cubic root of 218785985 is about 602.5686038397.

The spelling of 218785985 in words is "two hundred eighteen million, seven hundred eighty-five thousand, nine hundred eighty-five".