66765712039 has 4 divisors (see below), whose sum is σ = 71901536056. Its totient is φ = 61629888024.

The previous prime is 66765712021. The next prime is 66765712063. The reversal of 66765712039 is 93021756766.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 66765712039 - 2⁷ = 66765711911 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 (66765712099) 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, 2567911989 + ... + 2567912014.

It is an arithmetic number, because the mean of its divisors is an integer number (17975384014).

Almost surely, 2^66765712039 is an apocalyptic number.

66765712039 is a deficient number, since it is larger than the sum of its proper divisors (5135824017).

66765712039 is a wasteful number, since it uses less digits than its factorization.

66765712039 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5135824016.

The product of its (nonzero) digits is 2857680, while the sum is 52.

The spelling of 66765712039 in words is "sixty-six billion, seven hundred sixty-five million, seven hundred twelve thousand, thirty-nine".