18556985 has 8 divisors (see below), whose sum is σ = 22302216. Its totient is φ = 14823040.

The previous prime is 18556981. The next prime is 18556991. The reversal of 18556985 is 58965581.

It can be written as a sum of positive squares in 4 ways, for example, as 477481 + 18079504 = 691^2 + 4252^2 .

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

It is not a de Polignac number, because 18556985 - 2² = 18556981 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18556981) 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, 1367 + ... + 6243.

It is an arithmetic number, because the mean of its divisors is an integer number (2787777).

Almost surely, 2^18556985 is an apocalyptic number.

It is an amenable number.

18556985 is a deficient number, since it is larger than the sum of its proper divisors (3745231).

18556985 is an equidigital number, since it uses as much as digits as its factorization.

18556985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5643.

The product of its digits is 432000, while the sum is 47.

The square root of 18556985 is about 4307.7819118428. The cubic root of 18556985 is about 264.7499005036.

The spelling of 18556985 in words is "eighteen million, five hundred fifty-six thousand, nine hundred eighty-five".