218584081 has 4 divisors (see below), whose sum is σ = 219161200. Its totient is φ = 218006964.

The previous prime is 218584063. The next prime is 218584087. The reversal of 218584081 is 180485812.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 218584081 - 2²⁷ = 84366353 is a prime.

It is a super-2 number, since 2×218584081² = 95558000933229122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 218584081.

It is not an unprimeable number, because it can be changed into a prime (218584087) 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 3 ways as a sum of consecutive naturals, for example, 287991 + ... + 288748.

It is an arithmetic number, because the mean of its divisors is an integer number (54790300).

Almost surely, 2^218584081 is an apocalyptic number.

It is an amenable number.

218584081 is a deficient number, since it is larger than the sum of its proper divisors (577119).

218584081 is an equidigital number, since it uses as much as digits as its factorization.

218584081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 577118.

The product of its (nonzero) digits is 20480, while the sum is 37.

The square root of 218584081 is about 14784.5893077894. The cubic root of 218584081 is about 602.3831890761.

The spelling of 218584081 in words is "two hundred eighteen million, five hundred eighty-four thousand, eighty-one".