12907558721 has 4 divisors (see below), whose sum is σ = 12908223444. Its totient is φ = 12906894000.

The previous prime is 12907558687. The next prime is 12907558747. The reversal of 12907558721 is 12785570921.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12785570921 = 7873 ⋅1623977.

It can be written as a sum of positive squares in 2 ways, for example, as 886848400 + 12020710321 = 29780^2 + 109639^2 .

It is a cyclic number.

It is not a de Polignac number, because 12907558721 - 2¹⁰ = 12907557697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12907555721) 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, 302330 + ... + 342371.

It is an arithmetic number, because the mean of its divisors is an integer number (3227055861).

Almost surely, 2^12907558721 is an apocalyptic number.

It is an amenable number.

12907558721 is a deficient number, since it is larger than the sum of its proper divisors (664723).

12907558721 is an equidigital number, since it uses as much as digits as its factorization.

12907558721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 664722.

The product of its (nonzero) digits is 352800, while the sum is 47.

The spelling of 12907558721 in words is "twelve billion, nine hundred seven million, five hundred fifty-eight thousand, seven hundred twenty-one".