255921 has 8 divisors (see below), whose sum is σ = 356160. Its totient is φ = 163152.

The previous prime is 255919. The next prime is 255923. The reversal of 255921 is 129552.

It is an interprime number because it is at equal distance from previous prime (255919) and next prime (255923).

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

It is not a de Polignac number, because 255921 - 2¹ = 255919 is a prime.

It is a Curzon number.

255921 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 255891 and 255900.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 255921.

It is not an unprimeable number, because it can be changed into a prime (255923) 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, 1786 + ... + 1923.

It is an arithmetic number, because the mean of its divisors is an integer number (44520).

2²⁵⁵⁹²¹ is an apocalyptic number.

It is an amenable number.

255921 is a deficient number, since it is larger than the sum of its proper divisors (100239).

255921 is a wasteful number, since it uses less digits than its factorization.

255921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3735.

The product of its digits is 900, while the sum is 24.

The square root of 255921 is about 505.8863508734. The cubic root of 255921 is about 63.4895099128.

It can be divided in two parts, 255 and 921, that added together give a triangular number (1176 = T₄₈).

The spelling of 255921 in words is "two hundred fifty-five thousand, nine hundred twenty-one".