255685 has 4 divisors (see below), whose sum is σ = 306828. Its totient is φ = 204544.

The previous prime is 255679. The next prime is 255709. The reversal of 255685 is 586552.

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 173889 + 81796 = 417^2 + 286^2 .

It is a cyclic number.

It is not a de Polignac number, because 255685 - 2⁵ = 255653 is a prime.

It is a Duffinian number.

255685 is a lucky number.

It is a congruent number.

It is an unprimeable number.

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, 25564 + ... + 25573.

It is an arithmetic number, because the mean of its divisors is an integer number (76707).

2²⁵⁵⁶⁸⁵ is an apocalyptic number.

It is an amenable number.

255685 is a deficient number, since it is larger than the sum of its proper divisors (51143).

255685 is an equidigital number, since it uses as much as digits as its factorization.

255685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51142.

The product of its digits is 12000, while the sum is 31.

The square root of 255685 is about 505.6530431037. The cubic root of 255685 is about 63.4699880911.

The spelling of 255685 in words is "two hundred fifty-five thousand, six hundred eighty-five".