664013665 has 16 divisors (see below), whose sum is σ = 911066112. Its totient is φ = 455114304.

The previous prime is 664013641. The next prime is 664013681. The reversal of 664013665 is 566310466.

It is a cyclic number.

It is not a de Polignac number, because 664013665 - 2⁵ = 664013633 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 (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 142147 + ... + 146743.

It is an arithmetic number, because the mean of its divisors is an integer number (56941632).

Almost surely, 2^664013665 is an apocalyptic number.

It is an amenable number.

664013665 is a deficient number, since it is larger than the sum of its proper divisors (247052447).

664013665 is a wasteful number, since it uses less digits than its factorization.

664013665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8736.

The product of its (nonzero) digits is 77760, while the sum is 37.

The square root of 664013665 is about 25768.4626045094. The cubic root of 664013665 is about 872.4201189583.

The spelling of 664013665 in words is "six hundred sixty-four million, thirteen thousand, six hundred sixty-five".