18507990 has 16 divisors (see below), whose sum is σ = 44419248. Its totient is φ = 4935456.

The previous prime is 18507977. The next prime is 18508001. The reversal of 18507990 is 9970581.

It is a happy number.

It is a Curzon number.

It is a congruent 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, 308437 + ... + 308496.

It is an arithmetic number, because the mean of its divisors is an integer number (2776203).

Almost surely, 2^18507990 is an apocalyptic number.

18507990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18507990 is an abundant number, since it is smaller than the sum of its proper divisors (25911258).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18507990 is a wasteful number, since it uses less digits than its factorization.

18507990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 616943.

The product of its (nonzero) digits is 22680, while the sum is 39.

The square root of 18507990 is about 4302.0913518892. The cubic root of 18507990 is about 264.5166935456.

The spelling of 18507990 in words is "eighteen million, five hundred seven thousand, nine hundred ninety".