189128889 has 12 divisors (see below), whose sum is σ = 273526500. Its totient is φ = 125928864.

The previous prime is 189128881. The next prime is 189128899. The reversal of 189128889 is 988821981.

189128889 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 89927289 + 99201600 = 9483^2 + 9960^2 .

It is not a de Polignac number, because 189128889 - 2³ = 189128881 is a prime.

It is not an unprimeable number, because it can be changed into a prime (189128881) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5214 + ... + 20135.

It is an arithmetic number, because the mean of its divisors is an integer number (22793875).

Almost surely, 2^189128889 is an apocalyptic number.

It is an amenable number.

189128889 is a deficient number, since it is larger than the sum of its proper divisors (84397611).

189128889 is a wasteful number, since it uses less digits than its factorization.

189128889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26184 (or 26181 counting only the distinct ones).

The product of its digits is 663552, while the sum is 54.

The square root of 189128889 is about 13752.4139335609. The cubic root of 189128889 is about 574.0097779862.

The spelling of 189128889 in words is "one hundred eighty-nine million, one hundred twenty-eight thousand, eight hundred eighty-nine".