256728945 has 32 divisors (see below), whose sum is σ = 449639424. Its totient is φ = 124049600.

The previous prime is 256728889. The next prime is 256728947. The reversal of 256728945 is 549827652.

It is not a de Polignac number, because 256728945 - 2¹³ = 256720753 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 256728894 and 256728903.

It is not an unprimeable number, because it can be changed into a prime (256728947) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 48814 + ... + 53816.

It is an arithmetic number, because the mean of its divisors is an integer number (14051232).

Almost surely, 2^256728945 is an apocalyptic number.

It is an amenable number.

256728945 is a deficient number, since it is larger than the sum of its proper divisors (192910479).

256728945 is a wasteful number, since it uses less digits than its factorization.

256728945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5333.

The product of its digits is 1209600, while the sum is 48.

The square root of 256728945 is about 16022.7633384507. The cubic root of 256728945 is about 635.5625205316.

The spelling of 256728945 in words is "two hundred fifty-six million, seven hundred twenty-eight thousand, nine hundred forty-five".