128389389 has 8 divisors (see below), whose sum is σ = 181255680. Its totient is φ = 80558016.

The previous prime is 128389367. The next prime is 128389439. The reversal of 128389389 is 983983821.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 128389389 - 2¹⁵ = 128356621 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (51), and also a Moran number because the ratio is a prime number: 2517439 = 128389389 / (1 + 2 + 8 + 3 + 8 + 9 + 3 + 8 + 9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128389319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1258669 + ... + 1258770.

It is an arithmetic number, because the mean of its divisors is an integer number (22656960).

Almost surely, 2^128389389 is an apocalyptic number.

It is an amenable number.

128389389 is a deficient number, since it is larger than the sum of its proper divisors (52866291).

128389389 is a wasteful number, since it uses less digits than its factorization.

128389389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2517459.

The product of its digits is 746496, while the sum is 51.

The square root of 128389389 is about 11330.9041563328. The cubic root of 128389389 is about 504.4789436583.

It can be divided in two parts, 128389 and 389, that added together give a triangular number (128778 = T₅₀₇).

The spelling of 128389389 in words is "one hundred twenty-eight million, three hundred eighty-nine thousand, three hundred eighty-nine".