255981 has 8 divisors (see below), whose sum is σ = 372384. Its totient is φ = 155120.

The previous prime is 255977. The next prime is 255989. The reversal of 255981 is 189552.

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

It is a cyclic number.

It is not a de Polignac number, because 255981 - 2² = 255977 is a prime.

It is a super-2 number, since 2×255981² = 131052544722, which contains 22 as substring.

It is a Curzon 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 255981.

It is not an unprimeable number, because it can be changed into a prime (255989) 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, 3846 + ... + 3911.

It is an arithmetic number, because the mean of its divisors is an integer number (46548).

2²⁵⁵⁹⁸¹ is an apocalyptic number.

It is an amenable number.

255981 is a deficient number, since it is larger than the sum of its proper divisors (116403).

255981 is a wasteful number, since it uses less digits than its factorization.

255981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7771.

The product of its digits is 3600, while the sum is 30.

The square root of 255981 is about 505.9456492549. The cubic root of 255981 is about 63.4944711742.

It can be divided in two parts, 25 and 5981, that added together give a palindrome (6006).

The spelling of 255981 in words is "two hundred fifty-five thousand, nine hundred eighty-one".