18508989 has 16 divisors (see below), whose sum is σ = 25862400. Its totient is φ = 11758656.

The previous prime is 18508981. The next prime is 18508993. The reversal of 18508989 is 98980581.

It is not a de Polignac number, because 18508989 - 2³ = 18508981 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18508981) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5527 + ... + 8219.

It is an arithmetic number, because the mean of its divisors is an integer number (1616400).

Almost surely, 2^18508989 is an apocalyptic number.

It is an amenable number.

18508989 is a deficient number, since it is larger than the sum of its proper divisors (7353411).

18508989 is a wasteful number, since it uses less digits than its factorization.

18508989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2804.

The product of its (nonzero) digits is 207360, while the sum is 48.

The square root of 18508989 is about 4302.2074566436. The cubic root of 18508989 is about 264.5214527050.

The spelling of 18508989 in words is "eighteen million, five hundred eight thousand, nine hundred eighty-nine".