12718681721 has 4 divisors (see below), whose sum is σ = 12725495952. Its totient is φ = 12711867492.

The previous prime is 12718681693. The next prime is 12718681727.

12718681721 is nontrivially palindromic in base 10.

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.

It is a cyclic number.

It is not a de Polignac number, because 12718681721 - 2¹⁰ = 12718680697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12718681727) 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, 3404315 + ... + 3408048.

It is an arithmetic number, because the mean of its divisors is an integer number (3181373988).

Almost surely, 2^12718681721 is an apocalyptic number.

It is an amenable number.

12718681721 is a deficient number, since it is larger than the sum of its proper divisors (6814231).

12718681721 is an equidigital number, since it uses as much as digits as its factorization.

12718681721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6814230.

The product of its digits is 75264, while the sum is 44.

The spelling of 12718681721 in words is "twelve billion, seven hundred eighteen million, six hundred eighty-one thousand, seven hundred twenty-one".