218585081 has 16 divisors (see below), whose sum is σ = 257345088. Its totient is φ = 183038400.

The previous prime is 218585071. The next prime is 218585083. The reversal of 218585081 is 180585812.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-218585081 is a prime.

It is a super-2 number, since 2×218585081² = 95558875271553122, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (218585083) 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 15 ways as a sum of consecutive naturals, for example, 80315 + ... + 82991.

It is an arithmetic number, because the mean of its divisors is an integer number (16084068).

Almost surely, 2^218585081 is an apocalyptic number.

It is an amenable number.

218585081 is a deficient number, since it is larger than the sum of its proper divisors (38760007).

218585081 is a wasteful number, since it uses less digits than its factorization.

218585081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3272.

The product of its (nonzero) digits is 25600, while the sum is 38.

The square root of 218585081 is about 14784.6231267490. The cubic root of 218585081 is about 602.3841076887.

The spelling of 218585081 in words is "two hundred eighteen million, five hundred eighty-five thousand, eighty-one".