646256 has 30 divisors (see below), whose sum is σ = 1361520. Its totient is φ = 297024.

The previous prime is 646253. The next prime is 646259. The reversal of 646256 is 652646.

646256 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (646253) and next prime (646259).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 646256.

It is not an unprimeable number, because it can be changed into a prime (646253) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2585 + ... + 2823.

It is an arithmetic number, because the mean of its divisors is an integer number (45384).

2⁶⁴⁶²⁵⁶ 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 646256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (680760).

646256 is an abundant number, since it is smaller than the sum of its proper divisors (715264).

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

646256 is a wasteful number, since it uses less digits than its factorization.

646256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 273 (or 254 counting only the distinct ones).

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

The square root of 646256 is about 803.9004913545. The cubic root of 646256 is about 86.4572722697.

The spelling of 646256 in words is "six hundred forty-six thousand, two hundred fifty-six".