66600072009 has 24 divisors (see below), whose sum is σ = 96465358080. Its totient is φ = 44277728352.

The previous prime is 66600071987. The next prime is 66600072043. The reversal of 66600072009 is 90027000666.

66600072009 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 66600072009 - 2⁹ = 66600071497 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66600072509) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13389847 + ... + 13394819.

It is an arithmetic number, because the mean of its divisors is an integer number (4019389920).

Almost surely, 2^66600072009 is an apocalyptic number.

It is an amenable number.

66600072009 is a deficient number, since it is larger than the sum of its proper divisors (29865286071).

66600072009 is a wasteful number, since it uses less digits than its factorization.

66600072009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8781 (or 8778 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 36.

The spelling of 66600072009 in words is "sixty-six billion, six hundred million, seventy-two thousand, nine".