664256 has 28 divisors (see below), whose sum is σ = 1344168. Its totient is φ = 325632.

The previous prime is 664253. The next prime is 664271. The reversal of 664256 is 652466.

Its product of digits (8640) is a multiple of the sum of its prime factors (216).

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 664256.

It is not an unprimeable number, because it can be changed into a prime (664253) 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, 6155 + ... + 6261.

It is an arithmetic number, because the mean of its divisors is an integer number (48006).

2⁶⁶⁴²⁵⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (672084).

664256 is an abundant number, since it is smaller than the sum of its proper divisors (679912).

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

664256 is a wasteful number, since it uses less digits than its factorization.

664256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216 (or 206 counting only the distinct ones).

The product of its digits is 8640, while the sum is 29.

The square root of 664256 is about 815.0190181830. The cubic root of 664256 is about 87.2526237364.

The spelling of 664256 in words is "six hundred sixty-four thousand, two hundred fifty-six".