18739985 has 32 divisors (see below), whose sum is σ = 26265600. Its totient is φ = 12692160.

The previous prime is 18739979. The next prime is 18739999. The reversal of 18739985 is 58993781.

It is not a de Polignac number, because 18739985 - 2¹⁰ = 18738961 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 82442 + ... + 82668.

It is an arithmetic number, because the mean of its divisors is an integer number (820800).

Almost surely, 2^18739985 is an apocalyptic number.

It is an amenable number.

18739985 is a deficient number, since it is larger than the sum of its proper divisors (7525615).

18739985 is a wasteful number, since it uses less digits than its factorization.

18739985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 341.

The product of its digits is 544320, while the sum is 50.

The square root of 18739985 is about 4328.9704318695. The cubic root of 18739985 is about 265.6173337580.

The spelling of 18739985 in words is "eighteen million, seven hundred thirty-nine thousand, nine hundred eighty-five".