256690065 has 16 divisors (see below), whose sum is σ = 416835648. Its totient is φ = 134857536.

The previous prime is 256690043. The next prime is 256690067. The reversal of 256690065 is 560096652.

It is not a de Polignac number, because 256690065 - 2⁶ = 256690001 is a prime.

It is not an unprimeable number, because it can be changed into a prime (256690067) 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, 126702 + ... + 128711.

It is an arithmetic number, because the mean of its divisors is an integer number (26052228).

Almost surely, 2^256690065 is an apocalyptic number.

It is an amenable number.

256690065 is a deficient number, since it is larger than the sum of its proper divisors (160145583).

256690065 is a wasteful number, since it uses less digits than its factorization.

256690065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255488.

The product of its (nonzero) digits is 97200, while the sum is 39.

The square root of 256690065 is about 16021.5500186468. The cubic root of 256690065 is about 635.5304349165.

The spelling of 256690065 in words is "two hundred fifty-six million, six hundred ninety thousand, sixty-five".