18509975 has 36 divisors (see below), whose sum is σ = 26222280. Its totient is φ = 12936000.

The previous prime is 18509941. The next prime is 18509977. The reversal of 18509975 is 57990581.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-18509975 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18509977) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 87620 + ... + 87830.

Almost surely, 2^18509975 is an apocalyptic number.

18509975 is a deficient number, since it is larger than the sum of its proper divisors (7712305).

18509975 is a wasteful number, since it uses less digits than its factorization.

18509975 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 272 (or 256 counting only the distinct ones).

The product of its (nonzero) digits is 113400, while the sum is 44.

The square root of 18509975 is about 4302.3220474530. The cubic root of 18509975 is about 264.5261497654.

The spelling of 18509975 in words is "eighteen million, five hundred nine thousand, nine hundred seventy-five".