256741609 has 4 divisors (see below), whose sum is σ = 260357760. Its totient is φ = 253125460.

The previous prime is 256741603. The next prime is 256741613. The reversal of 256741609 is 906147652.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 256741609 - 2³ = 256741601 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256741601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1807969 + ... + 1808110.

It is an arithmetic number, because the mean of its divisors is an integer number (65089440).

Almost surely, 2^256741609 is an apocalyptic number.

It is an amenable number.

256741609 is a deficient number, since it is larger than the sum of its proper divisors (3616151).

256741609 is an equidigital number, since it uses as much as digits as its factorization.

256741609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3616150.

The product of its (nonzero) digits is 90720, while the sum is 40.

The square root of 256741609 is about 16023.1585213403. The cubic root of 256741609 is about 635.5729707640.

The spelling of 256741609 in words is "two hundred fifty-six million, seven hundred forty-one thousand, six hundred nine".