64388665 has 16 divisors (see below), whose sum is σ = 84859776. Its totient is φ = 46512000.

The previous prime is 64388657. The next prime is 64388717. The reversal of 64388665 is 56688346.

It is not a de Polignac number, because 64388665 - 2³ = 64388657 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 (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4429 + ... + 12181.

It is an arithmetic number, because the mean of its divisors is an integer number (5303736).

Almost surely, 2^64388665 is an apocalyptic number.

It is an amenable number.

64388665 is a deficient number, since it is larger than the sum of its proper divisors (20471111).

64388665 is a wasteful number, since it uses less digits than its factorization.

64388665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7920.

The product of its digits is 829440, while the sum is 46.

The square root of 64388665 is about 8024.2547940603. The cubic root of 64388665 is about 400.8080851467.

The spelling of 64388665 in words is "sixty-four million, three hundred eighty-eight thousand, six hundred sixty-five".