12911520509 has 4 divisors (see below), whose sum is σ = 13591074240. Its totient is φ = 12231966780.

The previous prime is 12911520493. The next prime is 12911520521. The reversal of 12911520509 is 90502511921.

12911520509 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 90502511921 = 9679 ⋅9350399.

It is a cyclic number.

It is not a de Polignac number, because 12911520509 - 2⁴ = 12911520493 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12911520569) 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 3 ways as a sum of consecutive naturals, for example, 339776837 + ... + 339776874.

It is an arithmetic number, because the mean of its divisors is an integer number (3397768560).

Almost surely, 2^12911520509 is an apocalyptic number.

12911520509 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

12911520509 is a deficient number, since it is larger than the sum of its proper divisors (679553731).

12911520509 is an equidigital number, since it uses as much as digits as its factorization.

12911520509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 679553730.

The product of its (nonzero) digits is 8100, while the sum is 35.

The spelling of 12911520509 in words is "twelve billion, nine hundred eleven million, five hundred twenty thousand, five hundred nine".