9990000666 has 96 divisors (see below), whose sum is σ = 24297781248. Its totient is φ = 2950940160.

The previous prime is 9990000661. The next prime is 9990000667. The reversal of 9990000666 is 6660000999.

It is a super-2 number, since 2×9990000666² (a number of 21 digits) contains 22 as substring.

9990000666 is a strobogrammatic number because it is the same when read upside-down.

It is a zygodrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (9990000661) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 336751 + ... + 365213.

It is an arithmetic number, because the mean of its divisors is an integer number (253101888).

Almost surely, 2^9990000666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9990000666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12148890624).

9990000666 is an abundant number, since it is smaller than the sum of its proper divisors (14307780582).

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

9990000666 is a wasteful number, since it uses less digits than its factorization.

9990000666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28556 (or 28553 counting only the distinct ones).

The product of its (nonzero) digits is 157464, while the sum is 45.

The square root of 9990000666 is about 99949.9908254123. The cubic root of 9990000666 is about 2153.7163534809.

The spelling of 9990000666 in words is "nine billion, nine hundred ninety million, six hundred sixty-six", and thus it is an aban number.