256161616800769 has 4 divisors (see below), whose sum is σ = 256770076698580. Its totient is φ = 255553156902960.

The previous prime is 256161616800751. The next prime is 256161616800779. The reversal of 256161616800769 is 967008616161652.

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 2212691950144 + 253948924850625 = 1487512^2 + 15935775^2 .

It is a cyclic number.

It is not a de Polignac number, because 256161616800769 - 2³⁵ = 256127257062401 is a prime.

It is a super-2 number, since 2×256161616800769² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 256161616800769.

It is not an unprimeable number, because it can be changed into a prime (256161616800779) 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, 304229948274 + ... + 304229949115.

It is an arithmetic number, because the mean of its divisors is an integer number (64192519174645).

Almost surely, 2^{256161616800769} is an apocalyptic number.

It is an amenable number.

256161616800769 is a deficient number, since it is larger than the sum of its proper divisors (608459897811).

256161616800769 is an equidigital number, since it uses as much as digits as its factorization.

256161616800769 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 608459897810.

The product of its (nonzero) digits is 39191040, while the sum is 64.

The spelling of 256161616800769 in words is "two hundred fifty-six trillion, one hundred sixty-one billion, six hundred sixteen million, eight hundred thousand, seven hundred sixty-nine".