13517168921 has 4 divisors (see below), whose sum is σ = 13517753700. Its totient is φ = 13516584144.

The previous prime is 13517168851. The next prime is 13517168923. The reversal of 13517168921 is 12986171531.

13517168921 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 4707469321 + 8809699600 = 68611^2 + 93860^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13517168921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13517168923) 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, 256226 + ... + 304443.

It is an arithmetic number, because the mean of its divisors is an integer number (3379438425).

Almost surely, 2^13517168921 is an apocalyptic number.

It is an amenable number.

13517168921 is a deficient number, since it is larger than the sum of its proper divisors (584779).

13517168921 is an equidigital number, since it uses as much as digits as its factorization.

13517168921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 584778.

The product of its digits is 90720, while the sum is 44.

The spelling of 13517168921 in words is "thirteen billion, five hundred seventeen million, one hundred sixty-eight thousand, nine hundred twenty-one".