18910889 has 6 divisors (see below), whose sum is σ = 19092606. Its totient is φ = 18730880.

The previous prime is 18910861. The next prime is 18910891. The reversal of 18910889 is 98801981.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 1605289 + 17305600 = 1267^2 + 4160^2 .

It is not a de Polignac number, because 18910889 - 2²⁴ = 2133673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18910819) 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, 12029 + ... + 13509.

It is an arithmetic number, because the mean of its divisors is an integer number (3182101).

Almost surely, 2^18910889 is an apocalyptic number.

It is an amenable number.

18910889 is a deficient number, since it is larger than the sum of its proper divisors (181717).

18910889 is an equidigital number, since it uses as much as digits as its factorization.

18910889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1707 (or 1594 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 44.

The square root of 18910889 is about 4348.6651975060. The cubic root of 18910889 is about 266.4223461868.

The spelling of 18910889 in words is "eighteen million, nine hundred ten thousand, eight hundred eighty-nine".