255509 has 4 divisors (see below), whose sum is σ = 257004. Its totient is φ = 254016.

The previous prime is 255503. The next prime is 255511. The reversal of 255509 is 905552.

255509 is nontrivially palindromic in base 6.

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

It can be written as a sum of positive squares in 2 ways, for example, as 253009 + 2500 = 503^2 + 50^2 .

It is a cyclic number.

It is not a de Polignac number, because 255509 - 2⁸ = 255253 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (255503) 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, 452 + ... + 845.

It is an arithmetic number, because the mean of its divisors is an integer number (64251).

2²⁵⁵⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

255509 is a deficient number, since it is larger than the sum of its proper divisors (1495).

255509 is a wasteful number, since it uses less digits than its factorization.

255509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1494.

The product of its (nonzero) digits is 2250, while the sum is 26.

The square root of 255509 is about 505.4789807697. The cubic root of 255509 is about 63.4554216232.

It can be divided in two parts, 255 and 509, that multiplied together give a triangular number (129795 = T₅₀₉).

The spelling of 255509 in words is "two hundred fifty-five thousand, five hundred nine".