64865665 has 4 divisors (see below), whose sum is σ = 77838804. Its totient is φ = 51892528.

The previous prime is 64865657. The next prime is 64865711. The reversal of 64865665 is 56656846.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56656846 = 2 ⋅28328423.

It can be written as a sum of positive squares in 2 ways, for example, as 19289664 + 45576001 = 4392^2 + 6751^2 .

It is a cyclic number.

It is not a de Polignac number, because 64865665 - 2³ = 64865657 is a prime.

It is a Duffinian 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, 6486562 + ... + 6486571.

It is an arithmetic number, because the mean of its divisors is an integer number (19459701).

Almost surely, 2^64865665 is an apocalyptic number.

It is an amenable number.

64865665 is a deficient number, since it is larger than the sum of its proper divisors (12973139).

64865665 is a wasteful number, since it uses less digits than its factorization.

64865665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12973138.

The product of its digits is 1036800, while the sum is 46.

The square root of 64865665 is about 8053.9223363526. The cubic root of 64865665 is about 401.7953980575.

The spelling of 64865665 in words is "sixty-four million, eight hundred sixty-five thousand, six hundred sixty-five".