13723665217 has 4 divisors (see below), whose sum is σ = 13739314516. Its totient is φ = 13708015920.

The previous prime is 13723665209. The next prime is 13723665223. The reversal of 13723665217 is 71256632731.

13723665217 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.

It can be written as a sum of positive squares in 2 ways, for example, as 9880161201 + 3843504016 = 99399^2 + 61996^2 .

It is a cyclic number.

It is not a de Polignac number, because 13723665217 - 2³ = 13723665209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13723665247) 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, 7823334 + ... + 7825087.

It is an arithmetic number, because the mean of its divisors is an integer number (3434828629).

Almost surely, 2^13723665217 is an apocalyptic number.

It is an amenable number.

13723665217 is a deficient number, since it is larger than the sum of its proper divisors (15649299).

13723665217 is an equidigital number, since it uses as much as digits as its factorization.

13723665217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15649298.

The product of its digits is 317520, while the sum is 43.

The spelling of 13723665217 in words is "thirteen billion, seven hundred twenty-three million, six hundred sixty-five thousand, two hundred seventeen".