66388065 has 32 divisors (see below), whose sum is σ = 109330560. Its totient is φ = 34384896.

The previous prime is 66388013. The next prime is 66388073. The reversal of 66388065 is 56088366.

It is not a de Polignac number, because 66388065 - 2⁸ = 66387809 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 89466 + ... + 90204.

It is an arithmetic number, because the mean of its divisors is an integer number (3416580).

Almost surely, 2^66388065 is an apocalyptic number.

It is an amenable number.

66388065 is a deficient number, since it is larger than the sum of its proper divisors (42942495).

66388065 is a wasteful number, since it uses less digits than its factorization.

66388065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 913.

The product of its (nonzero) digits is 207360, while the sum is 42.

The square root of 66388065 is about 8147.8871494394. The cubic root of 66388065 is about 404.9145071791.

The spelling of 66388065 in words is "sixty-six million, three hundred eighty-eight thousand, sixty-five".