256327409 has 4 divisors (see below), whose sum is σ = 276044916. Its totient is φ = 236609904.

The previous prime is 256327399. The next prime is 256327439. The reversal of 256327409 is 904723652.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 144961600 + 111365809 = 12040^2 + 10553^2 .

It is a cyclic number.

It is not a de Polignac number, because 256327409 - 2¹² = 256323313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256327439) 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, 9858734 + ... + 9858759.

It is an arithmetic number, because the mean of its divisors is an integer number (69011229).

Almost surely, 2^256327409 is an apocalyptic number.

It is an amenable number.

256327409 is a deficient number, since it is larger than the sum of its proper divisors (19717507).

256327409 is a wasteful number, since it uses less digits than its factorization.

256327409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19717506.

The product of its (nonzero) digits is 90720, while the sum is 38.

The square root of 256327409 is about 16010.2282619580. The cubic root of 256327409 is about 635.2309978605.

The spelling of 256327409 in words is "two hundred fifty-six million, three hundred twenty-seven thousand, four hundred nine".