13509645361 has 9 divisors (see below), whose sum is σ = 13808784171. Its totient is φ = 13216859472.

The previous prime is 13509645349. The next prime is 13509645367. The reversal of 13509645361 is 16354690531.

It is a happy number.

The square root of 13509645361 is 116231.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 10069119025 + 3440526336 = 100345^2 + 58656^2 .

It is not a de Polignac number, because 13509645361 - 2⁵ = 13509645329 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13509645367) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 5461621 + ... + 5464093.

Almost surely, 2^13509645361 is an apocalyptic number.

13509645361 is the 116231-st square number.

13509645361 is the 58116-th centered octagonal number.

It is an amenable number.

13509645361 is a deficient number, since it is larger than the sum of its proper divisors (299138810).

13509645361 is an frugal number, since it uses more digits than its factorization.

13509645361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5040 (or 2520 counting only the distinct ones).

The product of its (nonzero) digits is 291600, while the sum is 43.

The spelling of 13509645361 in words is "thirteen billion, five hundred nine million, six hundred forty-five thousand, three hundred sixty-one".