13807317721 has 4 divisors (see below), whose sum is σ = 13810040244. Its totient is φ = 13804595200.

The previous prime is 13807317691. The next prime is 13807317739. The reversal of 13807317721 is 12771370831.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12771370831 = 929 ⋅13747439.

It can be written as a sum of positive squares in 2 ways, for example, as 1146567321 + 12660750400 = 33861^2 + 112520^2 .

It is a cyclic number.

It is not a de Polignac number, because 13807317721 - 2⁷ = 13807317593 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13807317751) 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, 1353640 + ... + 1363801.

It is an arithmetic number, because the mean of its divisors is an integer number (3452510061).

Almost surely, 2^13807317721 is an apocalyptic number.

It is an amenable number.

13807317721 is a deficient number, since it is larger than the sum of its proper divisors (2722523).

13807317721 is an equidigital number, since it uses as much as digits as its factorization.

13807317721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2722522.

The product of its (nonzero) digits is 49392, while the sum is 40.

The spelling of 13807317721 in words is "thirteen billion, eight hundred seven million, three hundred seventeen thousand, seven hundred twenty-one".