255631 has 4 divisors (see below), whose sum is σ = 258264. Its totient is φ = 253000.

The previous prime is 255617. The next prime is 255637. The reversal of 255631 is 136552.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 255631 - 2⁷ = 255503 is a prime.

It is a super-2 number, since 2×255631² = 130694416322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (255637) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1165 + ... + 1366.

It is an arithmetic number, because the mean of its divisors is an integer number (64566).

2²⁵⁵⁶³¹ is an apocalyptic number.

255631 is a deficient number, since it is larger than the sum of its proper divisors (2633).

255631 is a wasteful number, since it uses less digits than its factorization.

255631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2632.

The product of its digits is 900, while the sum is 22.

The square root of 255631 is about 505.5996439872. The cubic root of 255631 is about 63.4655195449.

The spelling of 255631 in words is "two hundred fifty-five thousand, six hundred thirty-one".