128644889 has 4 divisors (see below), whose sum is σ = 128755920. Its totient is φ = 128533860.

The previous prime is 128644883. The next prime is 128644927. The reversal of 128644889 is 988446821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 128644889 - 2²⁴ = 111867673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128644883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53759 + ... + 56100.

It is an arithmetic number, because the mean of its divisors is an integer number (32188980).

Almost surely, 2^128644889 is an apocalyptic number.

It is an amenable number.

128644889 is a deficient number, since it is larger than the sum of its proper divisors (111031).

128644889 is a wasteful number, since it uses less digits than its factorization.

128644889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111030.

The product of its digits is 884736, while the sum is 50.

The square root of 128644889 is about 11342.1730281283. The cubic root of 128644889 is about 504.8133663181.

The spelling of 128644889 in words is "one hundred twenty-eight million, six hundred forty-four thousand, eight hundred eighty-nine".