13665609 has 12 divisors (see below), whose sum is σ = 19779396. Its totient is φ = 9091872.

The previous prime is 13665607. The next prime is 13665623. The reversal of 13665609 is 90656631.

It can be written as a sum of positive squares in 2 ways, for example, as 2295225 + 11370384 = 1515^2 + 3372^2 .

It is not a de Polignac number, because 13665609 - 2¹ = 13665607 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (13665607) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4279 + ... + 6755.

It is an arithmetic number, because the mean of its divisors is an integer number (1648283).

Almost surely, 2^13665609 is an apocalyptic number.

It is an amenable number.

13665609 is a deficient number, since it is larger than the sum of its proper divisors (6113787).

13665609 is a wasteful number, since it uses less digits than its factorization.

13665609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3096 (or 3093 counting only the distinct ones).

The product of its (nonzero) digits is 29160, while the sum is 36.

The square root of 13665609 is about 3696.7024494812. The cubic root of 13665609 is about 239.0798622018.

The spelling of 13665609 in words is "thirteen million, six hundred sixty-five thousand, six hundred nine".