256565656601 has 4 divisors (see below), whose sum is σ = 256568718900. Its totient is φ = 256562594304.

The previous prime is 256565656591. The next prime is 256565656621. The reversal of 256565656601 is 106656565652.

256565656601 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 135096678025 + 121468978576 = 367555^2 + 348524^2 .

It is a cyclic number.

It is not a de Polignac number, because 256565656601 - 2²⁶ = 256498547737 is a prime.

It is a super-2 number, since 2×256565656601² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256565656621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1401836 + ... + 1574253.

It is an arithmetic number, because the mean of its divisors is an integer number (64142179725).

Almost surely, 2^256565656601 is an apocalyptic number.

It is an amenable number.

256565656601 is a deficient number, since it is larger than the sum of its proper divisors (3062299).

256565656601 is an equidigital number, since it uses as much as digits as its factorization.

256565656601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3062298.

The product of its (nonzero) digits is 9720000, while the sum is 53.

The spelling of 256565656601 in words is "two hundred fifty-six billion, five hundred sixty-five million, six hundred fifty-six thousand, six hundred one".