13187665 has 16 divisors (see below), whose sum is σ = 16916688. Its totient is φ = 9834496.

The previous prime is 13187659. The next prime is 13187701. The reversal of 13187665 is 56678131.

It can be written as a sum of positive squares in 8 ways, for example, as 104976 + 13082689 = 324^2 + 3617^2 .

It is a 3-Lehmer number, since φ(13187665) divides (13187665-1)³.

It is a cyclic number.

It is a Carmichael number.

It is not a de Polignac number, because 13187665 - 2⁵ = 13187633 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8919 + ... + 10291.

It is an arithmetic number, because the mean of its divisors is an integer number (1057293).

It is a Poulet number, since it divides 2^13187664-1.

Almost surely, 2^13187665 is an apocalyptic number.

It is an amenable number.

13187665 is a deficient number, since it is larger than the sum of its proper divisors (3729023).

13187665 is a wasteful number, since it uses less digits than its factorization.

13187665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1508.

The product of its digits is 30240, while the sum is 37.

The square root of 13187665 is about 3631.4824796493. The cubic root of 13187665 is about 236.2595117621.

The spelling of 13187665 in words is "thirteen million, one hundred eighty-seven thousand, six hundred sixty-five".