255666 has 8 divisors (see below), whose sum is σ = 511344. Its totient is φ = 85220.

The previous prime is 255659. The next prime is 255667. The reversal of 255666 is 666552.

255666 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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

255666 is an admirable number.

It is a Curzon number.

It is a plaindrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (255667) by changing a digit.

255666 is an untouchable number, because it is not equal to the sum of proper divisors of any 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, 21300 + ... + 21311.

It is an arithmetic number, because the mean of its divisors is an integer number (63918).

2²⁵⁵⁶⁶⁶ is an apocalyptic number.

255666 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

255666 is a wasteful number, since it uses less digits than its factorization.

255666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42616.

The product of its digits is 10800, while the sum is 30.

The square root of 255666 is about 505.6342551687. The cubic root of 255666 is about 63.4684158966.

The spelling of 255666 in words is "two hundred fifty-five thousand, six hundred sixty-six".