256355009 has 2 divisors, whose sum is σ = 256355010. Its totient is φ = 256355008.

The previous prime is 256355003. The next prime is 256355023. The reversal of 256355009 is 900553652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 143400625 + 112954384 = 11975^2 + 10628^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256355009 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 256355009.

It is not a weakly prime, because it can be changed into another prime (256355003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128177504 + 128177505.

It is an arithmetic number, because the mean of its divisors is an integer number (128177505).

Almost surely, 2^256355009 is an apocalyptic number.

It is an amenable number.

256355009 is a deficient number, since it is larger than the sum of its proper divisors (1).

256355009 is an equidigital number, since it uses as much as digits as its factorization.

256355009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40500, while the sum is 35.

The square root of 256355009 is about 16011.0901877417. The cubic root of 256355009 is about 635.2537964970.

The spelling of 256355009 in words is "two hundred fifty-six million, three hundred fifty-five thousand, nine".