12566657651 has 4 divisors (see below), whose sum is σ = 12657065400. Its totient is φ = 12476249904.

The previous prime is 12566657611. The next prime is 12566657659. The reversal of 12566657651 is 15675666521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15675666521 = 307 ⋅51060803.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12566657651 is a prime.

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 12566657651.

It is not an unprimeable number, because it can be changed into a prime (12566657659) 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, 45203666 + ... + 45203943.

It is an arithmetic number, because the mean of its divisors is an integer number (3164266350).

Almost surely, 2^12566657651 is an apocalyptic number.

12566657651 is a deficient number, since it is larger than the sum of its proper divisors (90407749).

12566657651 is an equidigital number, since it uses as much as digits as its factorization.

12566657651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90407748.

The product of its digits is 2268000, while the sum is 50.

The spelling of 12566657651 in words is "twelve billion, five hundred sixty-six million, six hundred fifty-seven thousand, six hundred fifty-one".