255609 has 8 divisors (see below), whose sum is σ = 378720. Its totient is φ = 170388.

The previous prime is 255589. The next prime is 255613. The reversal of 255609 is 906552.

255609 is a `hidden beast` number, since 2 + 55 + 609 = 666.

It is not a de Polignac number, because 255609 - 2⁹ = 255097 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 9467 = 255609 / (2 + 5 + 5 + 6 + 0 + 9).

It is not an unprimeable number, because it can be changed into a prime (255649) 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, 4707 + ... + 4760.

It is an arithmetic number, because the mean of its divisors is an integer number (47340).

2²⁵⁵⁶⁰⁹ is an apocalyptic number.

It is an amenable number.

255609 is a deficient number, since it is larger than the sum of its proper divisors (123111).

255609 is an equidigital number, since it uses as much as digits as its factorization.

255609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9476 (or 9470 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 27.

The square root of 255609 is about 505.5778871747. The cubic root of 255609 is about 63.4636988457.

It can be divided in two parts, 2 and 55609, that added together give a triangular number (55611 = T₃₃₃).

The spelling of 255609 in words is "two hundred fifty-five thousand, six hundred nine".