256539 has 4 divisors (see below), whose sum is σ = 342056. Its totient is φ = 171024.

The previous prime is 256517. The next prime is 256541. The reversal of 256539 is 935652.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 256539 - 2¹¹ = 254491 is a prime.

It is a D-number.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 256539.

It is not an unprimeable number, because it can be changed into a prime (256579) 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, 42754 + ... + 42759.

It is an arithmetic number, because the mean of its divisors is an integer number (85514).

2²⁵⁶⁵³⁹ is an apocalyptic number.

256539 is a deficient number, since it is larger than the sum of its proper divisors (85517).

256539 is an equidigital number, since it uses as much as digits as its factorization.

256539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85516.

The product of its digits is 8100, while the sum is 30.

The square root of 256539 is about 506.4967916976. The cubic root of 256539 is about 63.5405738174.

The spelling of 256539 in words is "two hundred fifty-six thousand, five hundred thirty-nine".