400256 has 32 divisors (see below), whose sum is σ = 826200. Its totient is φ = 193024.

The previous prime is 400249. The next prime is 400261. The reversal of 400256 is 652004.

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

It is an unprimeable number.

400256 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6755 + ... + 6813.

2⁴⁰⁰²⁵⁶ 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 400256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (413100).

400256 is an abundant number, since it is smaller than the sum of its proper divisors (425944).

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

400256 is an equidigital number, since it uses as much as digits as its factorization.

400256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126 (or 114 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 400256 is about 632.6578854326. The cubic root of 400256 is about 73.6963451551.

It can be divided in two parts, 400 and 256, that multiplied together give a square (102400 = 320²).

The spelling of 400256 in words is "four hundred thousand, two hundred fifty-six".