128539 has 4 divisors (see below), whose sum is σ = 129456. Its totient is φ = 127624.

The previous prime is 128521. The next prime is 128549. The reversal of 128539 is 935821.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 935821 = 53 ⋅17657.

It is a cyclic number.

It is not a de Polignac number, because 128539 - 2⁷ = 128411 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (128509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 199 + ... + 544.

It is an arithmetic number, because the mean of its divisors is an integer number (32364).

2¹²⁸⁵³⁹ is an apocalyptic number.

128539 is a deficient number, since it is larger than the sum of its proper divisors (917).

128539 is an equidigital number, since it uses as much as digits as its factorization.

128539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 916.

The product of its digits is 2160, while the sum is 28.

The square root of 128539 is about 358.5233604662. The cubic root of 128539 is about 50.4674822518.

The spelling of 128539 in words is "one hundred twenty-eight thousand, five hundred thirty-nine".