256400 has 30 divisors (see below), whose sum is σ = 616962. Its totient is φ = 102400.

The previous prime is 256393. The next prime is 256423. The reversal of 256400 is 4652.

256400 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 55696 + 200704 = 236^2 + 448^2 .

It is an unprimeable number.

256400 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 80 + ... + 720.

2²⁵⁶⁴⁰⁰ is an apocalyptic number.

256400 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 256400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (308481).

256400 is an abundant number, since it is smaller than the sum of its proper divisors (360562).

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

256400 is a wasteful number, since it uses less digits than its factorization.

256400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 659 (or 648 counting only the distinct ones).

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

The square root of 256400 is about 506.3595560469. The cubic root of 256400 is about 63.5290957245.

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

The spelling of 256400 in words is "two hundred fifty-six thousand, four hundred".