64578665 has 16 divisors (see below), whose sum is σ = 82364688. Its totient is φ = 48439296.

The previous prime is 64578643. The next prime is 64578671. The reversal of 64578665 is 56687546.

It can be written as a sum of positive squares in 8 ways, for example, as 10010896 + 54567769 = 3164^2 + 7387^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64578665 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23609 + ... + 26201.

It is an arithmetic number, because the mean of its divisors is an integer number (5147793).

Almost surely, 2^64578665 is an apocalyptic number.

It is an amenable number.

64578665 is a deficient number, since it is larger than the sum of its proper divisors (17786023).

64578665 is a wasteful number, since it uses less digits than its factorization.

64578665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2908.

The product of its digits is 1209600, while the sum is 47.

The square root of 64578665 is about 8036.0851787422. The cubic root of 64578665 is about 401.2019368355.

The spelling of 64578665 in words is "sixty-four million, five hundred seventy-eight thousand, six hundred sixty-five".