18105889 has 6 divisors (see below), whose sum is σ = 18752630. Its totient is φ = 17480736.

The previous prime is 18105863. The next prime is 18105929. The reversal of 18105889 is 98850181.

It can be written as a sum of positive squares in 3 ways, for example, as 966289 + 17139600 = 983^2 + 4140^2 .

It is not a de Polignac number, because 18105889 - 2⁹ = 18105377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18105809) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9924 + ... + 11605.

Almost surely, 2^18105889 is an apocalyptic number.

It is an amenable number.

18105889 is a deficient number, since it is larger than the sum of its proper divisors (646741).

18105889 is an equidigital number, since it uses as much as digits as its factorization.

18105889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21587 (or 21558 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 40.

The square root of 18105889 is about 4255.1015264033. The cubic root of 18105889 is about 262.5870381063.

The spelling of 18105889 in words is "eighteen million, one hundred five thousand, eight hundred eighty-nine".