13666689 has 6 divisors (see below), whose sum is σ = 19740786. Its totient is φ = 9111120.

The previous prime is 13666687. The next prime is 13666711. The reversal of 13666689 is 98666631.

It can be written as a sum of positive squares in only one way, i.e., 9734400 + 3932289 = 3120^2 + 1983^2 .

It is not a de Polignac number, because 13666689 - 2¹ = 13666687 is a prime.

It is a plaindrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (13666687) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 759252 + ... + 759269.

It is an arithmetic number, because the mean of its divisors is an integer number (3290131).

Almost surely, 2^13666689 is an apocalyptic number.

It is an amenable number.

13666689 is a deficient number, since it is larger than the sum of its proper divisors (6074097).

13666689 is a wasteful number, since it uses less digits than its factorization.

13666689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1518527 (or 1518524 counting only the distinct ones).

The product of its digits is 279936, while the sum is 45.

The square root of 13666689 is about 3696.8485227285. The cubic root of 13666689 is about 239.0861602367.

The spelling of 13666689 in words is "thirteen million, six hundred sixty-six thousand, six hundred eighty-nine".