9999006666 has 64 divisors (see below), whose sum is σ = 22079765376. Its totient is φ = 2993504000.

The previous prime is 9999006653. The next prime is 9999006673. The reversal of 9999006666 is 6666009999.

9999006666 is a strobogrammatic number because it is the same when read upside-down.

It is a zygodrome in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3711616 + ... + 3714308.

It is an arithmetic number, because the mean of its divisors is an integer number (344996334).

Almost surely, 2^9999006666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9999006666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11039882688).

9999006666 is an abundant number, since it is smaller than the sum of its proper divisors (12080758710).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

9999006666 is a wasteful number, since it uses less digits than its factorization.

9999006666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3367.

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

The square root of 9999006666 is about 99995.0332066548. The cubic root of 9999006666 is about 2154.3633518955.

The spelling of 9999006666 in words is "nine billion, nine hundred ninety-nine million, six thousand, six hundred sixty-six".