255909 has 4 divisors (see below), whose sum is σ = 341216. Its totient is φ = 170604.

The previous prime is 255907. The next prime is 255917. The reversal of 255909 is 909552.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 255909 - 2¹ = 255907 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 255909.

It is not an unprimeable number, because it can be changed into a prime (255907) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42649 + ... + 42654.

It is an arithmetic number, because the mean of its divisors is an integer number (85304).

2²⁵⁵⁹⁰⁹ is an apocalyptic number.

It is an amenable number.

255909 is a deficient number, since it is larger than the sum of its proper divisors (85307).

255909 is an equidigital number, since it uses as much as digits as its factorization.

255909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85306.

The product of its (nonzero) digits is 4050, while the sum is 30.

The square root of 255909 is about 505.8744903630. The cubic root of 255909 is about 63.4885175675.

The spelling of 255909 in words is "two hundred fifty-five thousand, nine hundred nine".