18011985 has 8 divisors (see below), whose sum is σ = 28819200. Its totient is φ = 9606384.

The previous prime is 18011977. The next prime is 18012017. The reversal of 18011985 is 58911081.

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

It is not a de Polignac number, because 18011985 - 2³ = 18011977 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 600385 + ... + 600414.

It is an arithmetic number, because the mean of its divisors is an integer number (3602400).

Almost surely, 2^18011985 is an apocalyptic number.

18011985 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18011985 is a deficient number, since it is larger than the sum of its proper divisors (10807215).

18011985 is a wasteful number, since it uses less digits than its factorization.

18011985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1200807.

The product of its (nonzero) digits is 2880, while the sum is 33.

The square root of 18011985 is about 4244.0528978796. The cubic root of 18011985 is about 262.1322924153.

The spelling of 18011985 in words is "eighteen million, eleven thousand, nine hundred eighty-five".