66660009999 has 16 divisors (see below), whose sum is σ = 97920019584. Its totient is φ = 40000004000.

The previous prime is 66660009991. The next prime is 66660010019. The reversal of 66660009999 is 99990006666.

66660009999 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 66660009999 - 2³ = 66660009991 is a prime.

66660009999 is a strobogrammatic number because it is the same when read upside-down.

66660009999 is a modest number, since divided by 9999 gives 6666 as remainder.

It is a zygodrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66660009991) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9996669 + ... + 10003334.

It is an arithmetic number, because the mean of its divisors is an integer number (6120001224).

Almost surely, 2^66660009999 is an apocalyptic number.

66660009999 is a deficient number, since it is larger than the sum of its proper divisors (31260009585).

66660009999 is a wasteful number, since it uses less digits than its factorization.

66660009999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20000118.

The product of its (nonzero) digits is 8503056, while the sum is 60.

The spelling of 66660009999 in words is "sixty-six billion, six hundred sixty million, nine thousand, nine hundred ninety-nine".