128389439 has 2 divisors, whose sum is σ = 128389440. Its totient is φ = 128389438.

The previous prime is 128389367. The next prime is 128389447. The reversal of 128389439 is 934983821.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 128389439 - 2¹⁶ = 128323903 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 128389393 and 128389402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128388439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64194719 + 64194720.

It is an arithmetic number, because the mean of its divisors is an integer number (64194720).

Almost surely, 2^128389439 is an apocalyptic number.

128389439 is a deficient number, since it is larger than the sum of its proper divisors (1).

128389439 is an equidigital number, since it uses as much as digits as its factorization.

128389439 is an evil number, because the sum of its binary digits is even.

The product of its digits is 373248, while the sum is 47.

The square root of 128389439 is about 11330.9063626878. The cubic root of 128389439 is about 504.4790091465.

The spelling of 128389439 in words is "one hundred twenty-eight million, three hundred eighty-nine thousand, four hundred thirty-nine".