9999990066 has 48 divisors (see below), whose sum is σ = 22013921664. Its totient is φ = 3026100000.

The previous prime is 9999990017. The next prime is 9999990097. The reversal of 9999990066 is 6600999999.

It is a Harshad number since it is a multiple of its sum of digits (66).

It is a zygodrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 9999989979 and 9999990006.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 536056 + ... + 554396.

It is an arithmetic number, because the mean of its divisors is an integer number (458623368).

Almost surely, 2^9999990066 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9999990066, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11006960832).

9999990066 is an abundant number, since it is smaller than the sum of its proper divisors (12013931598).

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

9999990066 is a wasteful number, since it uses less digits than its factorization.

9999990066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19119 (or 19108 counting only the distinct ones).

The product of its (nonzero) digits is 19131876, while the sum is 66.

The square root of 9999990066 is about 99999.9503299877. The cubic root of 9999990066 is about 2154.4339766265.

The spelling of 9999990066 in words is "nine billion, nine hundred ninety-nine million, nine hundred ninety thousand, sixty-six".