12565407505817 has 4 divisors (see below), whose sum is σ = 12571287436596. Its totient is φ = 12559527575040.

The previous prime is 12565407505769. The next prime is 12565407505829. The reversal of 12565407505817 is 71850570456521.

It is a happy number.

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 5250784348681 + 7314623157136 = 2291459^2 + 2704556^2 .

It is a cyclic number.

It is not a de Polignac number, because 12565407505817 - 2³⁶ = 12496688029081 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12565407505117) 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, 2939962184 + ... + 2939966457.

It is an arithmetic number, because the mean of its divisors is an integer number (3142821859149).

Almost surely, 2^{12565407505817} is an apocalyptic number.

It is an amenable number.

12565407505817 is a deficient number, since it is larger than the sum of its proper divisors (5879930779).

12565407505817 is an equidigital number, since it uses as much as digits as its factorization.

12565407505817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5879930778.

The product of its (nonzero) digits is 11760000, while the sum is 56.

The spelling of 12565407505817 in words is "twelve trillion, five hundred sixty-five billion, four hundred seven million, five hundred five thousand, eight hundred seventeen".