13056261721 has 2 divisors, whose sum is σ = 13056261722. Its totient is φ = 13056261720.

The previous prime is 13056261679. The next prime is 13056261761. The reversal of 13056261721 is 12716265031.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13056261696 + 25 = 114264^2 + 5^2 .

It is an emirp because it is prime and its reverse (12716265031) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 13056261721 - 2²⁵ = 13022707289 is a prime.

It is not a weakly prime, because it can be changed into another prime (13056261761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6528130860 + 6528130861.

It is an arithmetic number, because the mean of its divisors is an integer number (6528130861).

Almost surely, 2^13056261721 is an apocalyptic number.

It is an amenable number.

13056261721 is a deficient number, since it is larger than the sum of its proper divisors (1).

13056261721 is an equidigital number, since it uses as much as digits as its factorization.

13056261721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15120, while the sum is 34.

The spelling of 13056261721 in words is "thirteen billion, fifty-six million, two hundred sixty-one thousand, seven hundred twenty-one".