256304565409 has 2 divisors, whose sum is σ = 256304565410. Its totient is φ = 256304565408.

The previous prime is 256304565389. The next prime is 256304565493. The reversal of 256304565409 is 904565403652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 199945805409 + 56358760000 = 447153^2 + 237400^2 .

It is a cyclic number.

It is not a de Polignac number, because 256304565409 - 2¹⁹ = 256304041121 is a prime.

It is not a weakly prime, because it can be changed into another prime (256304865409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128152282704 + 128152282705.

It is an arithmetic number, because the mean of its divisors is an integer number (128152282705).

Almost surely, 2^256304565409 is an apocalyptic number.

It is an amenable number.

256304565409 is a deficient number, since it is larger than the sum of its proper divisors (1).

256304565409 is an equidigital number, since it uses as much as digits as its factorization.

256304565409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888000, while the sum is 49.

The spelling of 256304565409 in words is "two hundred fifty-six billion, three hundred four million, five hundred sixty-five thousand, four hundred nine".