18685565 has 8 divisors (see below), whose sum is σ = 22495320. Its totient is φ = 14900032.

The previous prime is 18685561. The next prime is 18685571. The reversal of 18685565 is 56558681.

It can be written as a sum of positive squares in 4 ways, for example, as 1229881 + 17455684 = 1109^2 + 4178^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 18685565 - 2² = 18685561 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18685561) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4310 + ... + 7479.

It is an arithmetic number, because the mean of its divisors is an integer number (2811915).

Almost surely, 2^18685565 is an apocalyptic number.

It is an amenable number.

18685565 is a deficient number, since it is larger than the sum of its proper divisors (3809755).

18685565 is a wasteful number, since it uses less digits than its factorization.

18685565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12111.

The product of its digits is 288000, while the sum is 44.

The square root of 18685565 is about 4322.6803027751. The cubic root of 18685565 is about 265.3599712250.

The spelling of 18685565 in words is "eighteen million, six hundred eighty-five thousand, five hundred sixty-five".