256565407 has 16 divisors (see below), whose sum is σ = 303874560. Its totient is φ = 211948128.

The previous prime is 256565389. The next prime is 256565429. The reversal of 256565407 is 704565652.

It is not a de Polignac number, because 256565407 - 2⁷ = 256565279 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 256565407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256565447) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 195648 + ... + 196954.

It is an arithmetic number, because the mean of its divisors is an integer number (18992160).

Almost surely, 2^256565407 is an apocalyptic number.

256565407 is a deficient number, since it is larger than the sum of its proper divisors (47309153).

256565407 is a wasteful number, since it uses less digits than its factorization.

256565407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2310.

The product of its (nonzero) digits is 252000, while the sum is 40.

The square root of 256565407 is about 16017.6592234945. The cubic root of 256565407 is about 635.4275393862.

The spelling of 256565407 in words is "two hundred fifty-six million, five hundred sixty-five thousand, four hundred seven".