12566564657 has 8 divisors (see below), whose sum is σ = 12874537032. Its totient is φ = 12258662400.

The previous prime is 12566564623. The next prime is 12566564663. The reversal of 12566564657 is 75646566521.

12566564657 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 860190241 + 11706374416 = 29329^2 + 108196^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12566564657 - 2¹² = 12566560561 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12566564599 and 12566564608.

It is not an unprimeable number, because it can be changed into a prime (12566564617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 698657 + ... + 716417.

It is an arithmetic number, because the mean of its divisors is an integer number (1609317129).

Almost surely, 2^12566564657 is an apocalyptic number.

It is an amenable number.

12566564657 is a deficient number, since it is larger than the sum of its proper divisors (307972375).

12566564657 is a wasteful number, since it uses less digits than its factorization.

12566564657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35059.

The product of its digits is 9072000, while the sum is 53.

The spelling of 12566564657 in words is "twelve billion, five hundred sixty-six million, five hundred sixty-four thousand, six hundred fifty-seven".