9999888886666 has 48 divisors (see below), whose sum is σ = 17733267807552. Its totient is φ = 4216058078400.

The previous prime is 9999888886661. The next prime is 9999888886667. The reversal of 9999888886666 is 6666888889999.

9999888886666 is a strobogrammatic number because it is the same when read upside-down.

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (9999888886661) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1607401 + ... + 4752211.

It is an arithmetic number, because the mean of its divisors is an integer number (369443079324).

Almost surely, 2^{9999888886666} is an apocalyptic number.

9999888886666 is a deficient number, since it is larger than the sum of its proper divisors (7733378920886).

9999888886666 is a wasteful number, since it uses less digits than its factorization.

9999888886666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3145355 (or 3145348 counting only the distinct ones).

The product of its digits is 278628139008, while the sum is 100.

The spelling of 9999888886666 in words is "nine trillion, nine hundred ninety-nine billion, eight hundred eighty-eight million, eight hundred eighty-six thousand, six hundred sixty-six".