18985187 has 16 divisors (see below), whose sum is σ = 21111552. Its totient is φ = 16964640.

The previous prime is 18985177. The next prime is 18985207. The reversal of 18985187 is 78158981.

It is a cyclic number.

It is not a de Polignac number, because 18985187 - 2¹⁸ = 18723043 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18985157) 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 15 ways as a sum of consecutive naturals, for example, 61688 + ... + 61994.

It is an arithmetic number, because the mean of its divisors is an integer number (1319472).

Almost surely, 2^18985187 is an apocalyptic number.

18985187 is a deficient number, since it is larger than the sum of its proper divisors (2126365).

18985187 is a wasteful number, since it uses less digits than its factorization.

18985187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 458.

The product of its digits is 161280, while the sum is 47.

The square root of 18985187 is about 4357.1994445974. The cubic root of 18985187 is about 266.7708011700.

The spelling of 18985187 in words is "eighteen million, nine hundred eighty-five thousand, one hundred eighty-seven".