18156985 has 16 divisors (see below), whose sum is σ = 27165312. Its totient is φ = 11318400.

The previous prime is 18156977. The next prime is 18157001. The reversal of 18156985 is 58965181.

It is not a de Polignac number, because 18156985 - 2³ = 18156977 is a prime.

It is a super-2 number, since 2×18156985² = 659352208580450, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23196 + ... + 23965.

It is an arithmetic number, because the mean of its divisors is an integer number (1697832).

Almost surely, 2^18156985 is an apocalyptic number.

It is an amenable number.

18156985 is a deficient number, since it is larger than the sum of its proper divisors (9008327).

18156985 is a wasteful number, since it uses less digits than its factorization.

18156985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47184.

The product of its digits is 86400, while the sum is 43.

The square root of 18156985 is about 4261.1013834454. The cubic root of 18156985 is about 262.8338186923.

The spelling of 18156985 in words is "eighteen million, one hundred fifty-six thousand, nine hundred eighty-five".