255640 has 64 divisors (see below), whose sum is σ = 725760. Its totient is φ = 78720.

The previous prime is 255637. The next prime is 255641. The reversal of 255640 is 46552.

255640 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (255641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3039 + ... + 3121.

It is an arithmetic number, because the mean of its divisors is an integer number (11340).

2²⁵⁵⁶⁴⁰ is an apocalyptic number.

255640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 255640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (362880).

255640 is an abundant number, since it is smaller than the sum of its proper divisors (470120).

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

255640 is a wasteful number, since it uses less digits than its factorization.

255640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112 (or 108 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 255640 is about 505.6085442316. The cubic root of 255640 is about 63.4662643463.

It can be divided in two parts, 25 and 5640, that added together give a palindrome (5665).

The spelling of 255640 in words is "two hundred fifty-five thousand, six hundred forty".