128388439 has 2 divisors, whose sum is σ = 128388440. Its totient is φ = 128388438.

The previous prime is 128388433. The next prime is 128388451. The reversal of 128388439 is 934883821.

It is a weak prime.

It is an emirp because it is prime and its reverse (934883821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 128388439 - 2¹³ = 128380247 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128388433) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64194219 + 64194220.

It is an arithmetic number, because the mean of its divisors is an integer number (64194220).

Almost surely, 2^128388439 is an apocalyptic number.

128388439 is a deficient number, since it is larger than the sum of its proper divisors (1).

128388439 is an equidigital number, since it uses as much as digits as its factorization.

128388439 is an evil number, because the sum of its binary digits is even.

The product of its digits is 331776, while the sum is 46.

The square root of 128388439 is about 11330.8622355053. The cubic root of 128388439 is about 504.4776993806.

The spelling of 128388439 in words is "one hundred twenty-eight million, three hundred eighty-eight thousand, four hundred thirty-nine".