128239 has 2 divisors, whose sum is σ = 128240. Its totient is φ = 128238.

The previous prime is 128237. The next prime is 128257. The reversal of 128239 is 932821.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 128239 - 2¹ = 128237 is a prime.

It is a super-2 number, since 2×128239² = 32890482242, which contains 22 as substring.

Together with 128237, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128237) 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 as a sum of consecutive naturals, namely, 64119 + 64120.

It is an arithmetic number, because the mean of its divisors is an integer number (64120).

2¹²⁸²³⁹ is an apocalyptic number.

128239 is a deficient number, since it is larger than the sum of its proper divisors (1).

128239 is an equidigital number, since it uses as much as digits as its factorization.

128239 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 25.

The square root of 128239 is about 358.1047332834. The cubic root of 128239 is about 50.4281892779.

The spelling of 128239 in words is "one hundred twenty-eight thousand, two hundred thirty-nine".