128395639 has 2 divisors, whose sum is σ = 128395640. Its totient is φ = 128395638.

The previous prime is 128395633. The next prime is 128395691. The reversal of 128395639 is 936593821.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 128395639 - 2⁷ = 128395511 is a prime.

It is a super-2 number, since 2×128395639² = 32970880228436642, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128395633) 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 as a sum of consecutive naturals, namely, 64197819 + 64197820.

It is an arithmetic number, because the mean of its divisors is an integer number (64197820).

Almost surely, 2^128395639 is an apocalyptic number.

128395639 is a deficient number, since it is larger than the sum of its proper divisors (1).

128395639 is an equidigital number, since it uses as much as digits as its factorization.

128395639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 349920, while the sum is 46.

The square root of 128395639 is about 11331.1799473841. The cubic root of 128395639 is about 504.4871295431.

The spelling of 128395639 in words is "one hundred twenty-eight million, three hundred ninety-five thousand, six hundred thirty-nine".