64660565 has 4 divisors (see below), whose sum is σ = 77592684. Its totient is φ = 51728448.

The previous prime is 64660559. The next prime is 64660577. The reversal of 64660565 is 56506646.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15225604 + 49434961 = 3902^2 + 7031^2 .

It is a cyclic number.

It is not a de Polignac number, because 64660565 - 2⁶ = 64660501 is a prime.

It is a super-2 number, since 2×64660565² = 8361977332238450, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6466052 + ... + 6466061.

It is an arithmetic number, because the mean of its divisors is an integer number (19398171).

Almost surely, 2^64660565 is an apocalyptic number.

It is an amenable number.

64660565 is a deficient number, since it is larger than the sum of its proper divisors (12932119).

64660565 is a wasteful number, since it uses less digits than its factorization.

64660565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12932118.

The product of its (nonzero) digits is 129600, while the sum is 38.

The square root of 64660565 is about 8041.1793289293. The cubic root of 64660565 is about 401.3714693884.

The spelling of 64660565 in words is "sixty-four million, six hundred sixty thousand, five hundred sixty-five".