256663407 has 32 divisors (see below), whose sum is σ = 459486720. Its totient is φ = 123073920.

The previous prime is 256663373. The next prime is 256663409. The reversal of 256663407 is 704366652.

It is not a de Polignac number, because 256663407 - 2¹⁴ = 256647023 is a prime.

It is a super-2 number, since 2×256663407² = 131752208985695298, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256663409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 39732 + ... + 45737.

It is an arithmetic number, because the mean of its divisors is an integer number (14358960).

Almost surely, 2^256663407 is an apocalyptic number.

256663407 is a deficient number, since it is larger than the sum of its proper divisors (202823313).

256663407 is a wasteful number, since it uses less digits than its factorization.

256663407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85503.

The product of its (nonzero) digits is 181440, while the sum is 39.

The square root of 256663407 is about 16020.7180550686. The cubic root of 256663407 is about 635.5084336016.

The spelling of 256663407 in words is "two hundred fifty-six million, six hundred sixty-three thousand, four hundred seven".