13319311721 has 2 divisors, whose sum is σ = 13319311722. Its totient is φ = 13319311720.

The previous prime is 13319311711. The next prime is 13319311723. The reversal of 13319311721 is 12711391331.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10757838400 + 2561473321 = 103720^2 + 50611^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13319311721 is a prime.

Together with 13319311723, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (13319311723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6659655860 + 6659655861.

It is an arithmetic number, because the mean of its divisors is an integer number (6659655861).

Almost surely, 2^13319311721 is an apocalyptic number.

It is an amenable number.

13319311721 is a deficient number, since it is larger than the sum of its proper divisors (1).

13319311721 is an equidigital number, since it uses as much as digits as its factorization.

13319311721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3402, while the sum is 32.

The spelling of 13319311721 in words is "thirteen billion, three hundred nineteen million, three hundred eleven thousand, seven hundred twenty-one".