256209 has 8 divisors (see below), whose sum is σ = 350112. Its totient is φ = 166560.

The previous prime is 256199. The next prime is 256211. The reversal of 256209 is 902652.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 256209 - 2¹¹ = 254161 is a prime.

It is a Curzon number.

It is a nialpdrome in base 8.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 256209.

It is not an unprimeable number, because it can be changed into a prime (256219) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 919 + ... + 1164.

It is an arithmetic number, because the mean of its divisors is an integer number (43764).

2²⁵⁶²⁰⁹ is an apocalyptic number.

It is an amenable number.

256209 is a deficient number, since it is larger than the sum of its proper divisors (93903).

256209 is a wasteful number, since it uses less digits than its factorization.

256209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2127.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 256209 is about 506.1709197494. The cubic root of 256209 is about 63.5133169004.

It can be divided in two parts, 256 and 209, that added together give a triangular number (465 = T₃₀).

The spelling of 256209 in words is "two hundred fifty-six thousand, two hundred nine".