66000009 has 4 divisors (see below), whose sum is σ = 88000016. Its totient is φ = 44000004.

The previous prime is 66000007. The next prime is 66000013. The reversal of 66000009 is 90000066.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 66000009 - 2¹ = 66000007 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66000007) 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, 10999999 + ... + 11000004.

It is an arithmetic number, because the mean of its divisors is an integer number (22000004).

Almost surely, 2^66000009 is an apocalyptic number.

It is an amenable number.

66000009 is a deficient number, since it is larger than the sum of its proper divisors (22000007).

66000009 is a wasteful number, since it uses less digits than its factorization.

66000009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22000006.

The product of its (nonzero) digits is 324, while the sum is 21.

The square root of 66000009 is about 8124.0389585477. The cubic root of 66000009 is about 404.1240204315.

The spelling of 66000009 in words is "sixty-six million, nine", and thus it is an aban number and an uban number.