66065647 has 4 divisors (see below), whose sum is σ = 66548016. Its totient is φ = 65583280.

The previous prime is 66065627. The next prime is 66065651. The reversal of 66065647 is 74656066.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66065647 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66065617) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 240979 + ... + 241252.

It is an arithmetic number, because the mean of its divisors is an integer number (16637004).

Almost surely, 2^66065647 is an apocalyptic number.

66065647 is a deficient number, since it is larger than the sum of its proper divisors (482369).

66065647 is a wasteful number, since it uses less digits than its factorization.

66065647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 482368.

The product of its (nonzero) digits is 181440, while the sum is 40.

The square root of 66065647 is about 8128.0776940184. The cubic root of 66065647 is about 404.2579451801.

The spelling of 66065647 in words is "sixty-six million, sixty-five thousand, six hundred forty-seven".