256407 has 4 divisors (see below), whose sum is σ = 341880. Its totient is φ = 170936.

The previous prime is 256393. The next prime is 256423. The reversal of 256407 is 704652.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 256407 - 2⁴ = 256391 is a prime.

It is a D-number.

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 256407.

It is not an unprimeable number, because it can be changed into a prime (256307) 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, 42732 + ... + 42737.

It is an arithmetic number, because the mean of its divisors is an integer number (85470).

2²⁵⁶⁴⁰⁷ is an apocalyptic number.

256407 is a deficient number, since it is larger than the sum of its proper divisors (85473).

256407 is an equidigital number, since it uses as much as digits as its factorization.

256407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85472.

The product of its (nonzero) digits is 1680, while the sum is 24.

The square root of 256407 is about 506.3664680841. The cubic root of 256407 is about 63.5296738571.

The spelling of 256407 in words is "two hundred fifty-six thousand, four hundred seven".