18651985 has 8 divisors (see below), whose sum is σ = 24417216. Its totient is φ = 13565040.

The previous prime is 18651967. The next prime is 18651991. The reversal of 18651985 is 58915681.

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

It is not a de Polignac number, because 18651985 - 2⁵ = 18651953 is a prime.

It is a Duffinian 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, 169509 + ... + 169618.

It is an arithmetic number, because the mean of its divisors is an integer number (3052152).

Almost surely, 2^18651985 is an apocalyptic number.

It is an amenable number.

18651985 is a deficient number, since it is larger than the sum of its proper divisors (5765231).

18651985 is a wasteful number, since it uses less digits than its factorization.

18651985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 339143.

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

The square root of 18651985 is about 4318.7943919571. The cubic root of 18651985 is about 265.2009156286.

The spelling of 18651985 in words is "eighteen million, six hundred fifty-one thousand, nine hundred eighty-five".