256791280043569 has 2 divisors, whose sum is σ = 256791280043570. Its totient is φ = 256791280043568.

The previous prime is 256791280043509. The next prime is 256791280043611. The reversal of 256791280043569 is 965340082197652.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 214399526342544 + 42391753701025 = 14642388^2 + 6510895^2 .

It is a cyclic number.

It is not a de Polignac number, because 256791280043569 - 2²⁹ = 256790743172657 is a prime.

It is a super-2 number, since 2×256791280043569² (a number of 30 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (256791280043509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128395640021784 + 128395640021785.

It is an arithmetic number, because the mean of its divisors is an integer number (128395640021785).

It is a 1-persistent number, because it is pandigital, but 2⋅256791280043569 = 513582560087138 is not.

Almost surely, 2^{256791280043569} is an apocalyptic number.

It is an amenable number.

256791280043569 is a deficient number, since it is larger than the sum of its proper divisors (1).

256791280043569 is an equidigital number, since it uses as much as digits as its factorization.

256791280043569 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 195955200, while the sum is 67.

The spelling of 256791280043569 in words is "two hundred fifty-six trillion, seven hundred ninety-one billion, two hundred eighty million, forty-three thousand, five hundred sixty-nine".