13091707561 has 3 divisors (see below), whose sum is σ = 13091821981. Its totient is φ = 13091593142.

The previous prime is 13091707553. The next prime is 13091707609. The reversal of 13091707561 is 16570719031.

The square root of 13091707561 is 114419.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 13091707561 - 2³ = 13091707553 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13091707501) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 57210 + ... + 171628.

Almost surely, 2^13091707561 is an apocalyptic number.

13091707561 is the 114419-th square number.

13091707561 is the 57210-th centered octagonal number.

It is an amenable number.

13091707561 is a deficient number, since it is larger than the sum of its proper divisors (114420).

13091707561 is an frugal number, since it uses more digits than its factorization.

13091707561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228838 (or 114419 counting only the distinct ones).

The product of its (nonzero) digits is 39690, while the sum is 40.

The spelling of 13091707561 in words is "thirteen billion, ninety-one million, seven hundred seven thousand, five hundred sixty-one".