13640665 has 8 divisors (see below), whose sum is σ = 16417800. Its totient is φ = 10879872.

The previous prime is 13640639. The next prime is 13640677. The reversal of 13640665 is 56604631.

It can be written as a sum of positive squares in 4 ways, for example, as 76176 + 13564489 = 276^2 + 3683^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 13640665 - 2⁹ = 13640153 is a prime.

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 7 ways as a sum of consecutive naturals, for example, 2164 + ... + 5653.

It is an arithmetic number, because the mean of its divisors is an integer number (2052225).

Almost surely, 2^13640665 is an apocalyptic number.

It is an amenable number.

13640665 is a deficient number, since it is larger than the sum of its proper divisors (2777135).

13640665 is an equidigital number, since it uses as much as digits as its factorization.

13640665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8171.

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 13640665 is about 3693.3270908491. The cubic root of 13640665 is about 238.9343084923.

The spelling of 13640665 in words is "thirteen million, six hundred forty thousand, six hundred sixty-five".