664012565 has 8 divisors (see below), whose sum is σ = 824291640. Its totient is φ = 512892352.

The previous prime is 664012549. The next prime is 664012577. The reversal of 664012565 is 565210466.

It can be written as a sum of positive squares in 4 ways, for example, as 100140049 + 563872516 = 10007^2 + 23746^2 .

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 664012565 - 2⁴ = 664012549 is a prime.

It is a Curzon number.

It is a congruent 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 7 ways as a sum of consecutive naturals, for example, 2289554 + ... + 2289843.

It is an arithmetic number, because the mean of its divisors is an integer number (103036455).

Almost surely, 2^664012565 is an apocalyptic number.

It is an amenable number.

664012565 is a deficient number, since it is larger than the sum of its proper divisors (160279075).

664012565 is a wasteful number, since it uses less digits than its factorization.

664012565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4579431.

The product of its (nonzero) digits is 43200, while the sum is 35.

The square root of 664012565 is about 25768.4412605807. The cubic root of 664012565 is about 872.4196372099.

The spelling of 664012565 in words is "six hundred sixty-four million, twelve thousand, five hundred sixty-five".