12556911609 has 36 divisors (see below), whose sum is σ = 20142248308. Its totient is φ = 7531729920.

The previous prime is 12556911607. The next prime is 12556911611. The reversal of 12556911609 is 90611965521.

It is a happy number.

12556911609 is a `hidden beast` number, since 1 + 2 + 556 + 91 + 1 + 6 + 0 + 9 = 666.

It is an interprime number because it is at equal distance from previous prime (12556911607) and next prime (12556911611).

It can be written as a sum of positive squares in 2 ways, for example, as 7452523584 + 5104388025 = 86328^2 + 71445^2 .

It is not a de Polignac number, because 12556911609 - 2¹ = 12556911607 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (12556911607) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 46197 + ... + 165069.

Almost surely, 2^12556911609 is an apocalyptic number.

It is an amenable number.

12556911609 is a deficient number, since it is larger than the sum of its proper divisors (7585336699).

12556911609 is a wasteful number, since it uses less digits than its factorization.

12556911609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118998 (or 118984 counting only the distinct ones).

The product of its (nonzero) digits is 145800, while the sum is 45.

The spelling of 12556911609 in words is "twelve billion, five hundred fifty-six million, nine hundred eleven thousand, six hundred nine".