13165328261 has 4 divisors (see below), whose sum is σ = 13166404332. Its totient is φ = 13164252192.

The previous prime is 13165328219. The next prime is 13165328269. The reversal of 13165328261 is 16282356131.

It is a happy number.

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 4442889025 + 8722439236 = 66655^2 + 93394^2 .

It is a cyclic number.

It is not a de Polignac number, because 13165328261 - 2²⁶ = 13098219397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13165328269) 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, 519470 + ... + 544223.

It is an arithmetic number, because the mean of its divisors is an integer number (3291601083).

Almost surely, 2^13165328261 is an apocalyptic number.

It is an amenable number.

13165328261 is a deficient number, since it is larger than the sum of its proper divisors (1076071).

13165328261 is a wasteful number, since it uses less digits than its factorization.

13165328261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1076070.

The product of its digits is 51840, while the sum is 38.

The spelling of 13165328261 in words is "thirteen billion, one hundred sixty-five million, three hundred twenty-eight thousand, two hundred sixty-one".