256660 has 24 divisors (see below), whose sum is σ = 553896. Its totient is φ = 99840.

The previous prime is 256651. The next prime is 256661. The reversal of 256660 is 66652.

It can be written as a sum of positive squares in 4 ways, for example, as 24336 + 232324 = 156^2 + 482^2 .

It is a nialpdrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256661) 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, 664 + ... + 976.

It is an arithmetic number, because the mean of its divisors is an integer number (23079).

2²⁵⁶⁶⁶⁰ is an apocalyptic number.

256660 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 256660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (276948).

256660 is an abundant number, since it is smaller than the sum of its proper divisors (297236).

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

256660 is a wasteful number, since it uses less digits than its factorization.

256660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 363 (or 361 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 256660 is about 506.6162255593. The cubic root of 256660 is about 63.5505621635.

The spelling of 256660 in words is "two hundred fifty-six thousand, six hundred sixty".