18686889 has 16 divisors (see below), whose sum is σ = 29814400. Its totient is φ = 11499408.

The previous prime is 18686873. The next prime is 18686909. The reversal of 18686889 is 98868681.

It is not a de Polignac number, because 18686889 - 2⁴ = 18686873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18686819) 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, 26269 + ... + 26970.

It is an arithmetic number, because the mean of its divisors is an integer number (1863400).

Almost surely, 2^18686889 is an apocalyptic number.

It is an amenable number.

18686889 is a deficient number, since it is larger than the sum of its proper divisors (11127511).

18686889 is a wasteful number, since it uses less digits than its factorization.

18686889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53261 (or 53255 counting only the distinct ones).

The product of its digits is 1327104, while the sum is 54.

The square root of 18686889 is about 4322.8334457853. The cubic root of 18686889 is about 265.3662385996.

The spelling of 18686889 in words is "eighteen million, six hundred eighty-six thousand, eight hundred eighty-nine".