256404465 has 24 divisors (see below), whose sum is σ = 449023848. Its totient is φ = 135336960.

The previous prime is 256404451. The next prime is 256404469. The reversal of 256404465 is 564404652.

256404465 is a `hidden beast` number, since 2 + 5 + 640 + 4 + 4 + 6 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 7017201 + 249387264 = 2649^2 + 15792^2 .

It is not a de Polignac number, because 256404465 - 2⁸ = 256404209 is a prime.

It is not an unprimeable number, because it can be changed into a prime (256404469) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 25006 + ... + 33735.

It is an arithmetic number, because the mean of its divisors is an integer number (18709327).

Almost surely, 2^256404465 is an apocalyptic number.

It is an amenable number.

256404465 is a deficient number, since it is larger than the sum of its proper divisors (192619383).

256404465 is a wasteful number, since it uses less digits than its factorization.

256404465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58849 (or 58846 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 36.

The square root of 256404465 is about 16012.6345427603. The cubic root of 256404465 is about 635.2946449176.

The spelling of 256404465 in words is "two hundred fifty-six million, four hundred four thousand, four hundred sixty-five".