13465513681 has 3 divisors (see below), whose sum is σ = 13465629723. Its totient is φ = 13465397640.

The previous prime is 13465513667. The next prime is 13465513703. The reversal of 13465513681 is 18631556431.

The square root of 13465513681 is 116041.

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, and also an emirpimes, since its reverse is a distinct semiprime: 18631556431 = 9013 ⋅2067187.

It can be written as a sum of positive squares in only one way, i.e., 13261595281 + 203918400 = 115159^2 + 14280^2 .

It is a de Polignac number, because none of the positive numbers 2^k-13465513681 is a prime.

It is a super-2 number, since 2×13465513681² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13465513631) 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, 58021 + ... + 174061.

It is an arithmetic number, because the mean of its divisors is an integer number (4488543241).

Almost surely, 2^13465513681 is an apocalyptic number.

13465513681 is the 116041-st square number.

13465513681 is the 58021-st centered octagonal number.

It is an amenable number.

13465513681 is a deficient number, since it is larger than the sum of its proper divisors (116042).

13465513681 is an frugal number, since it uses more digits than its factorization.

13465513681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232082 (or 116041 counting only the distinct ones).

The product of its digits is 259200, while the sum is 43.

The spelling of 13465513681 in words is "thirteen billion, four hundred sixty-five million, five hundred thirteen thousand, six hundred eighty-one".