999888888666 has 64 divisors (see below), whose sum is σ = 2143794901248. Its totient is φ = 310091493888.

The previous prime is 999888888619. The next prime is 999888888673. The reversal of 999888888666 is 666888888999.

999888888666 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 a self number, because there is not a number n which added to its sum of digits gives 999888888666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17193510 + ... + 17251566.

It is an arithmetic number, because the mean of its divisors is an integer number (33496795332).

Almost surely, 2^999888888666 is an apocalyptic number.

999888888666 is an abundant number, since it is smaller than the sum of its proper divisors (1143906012582).

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

999888888666 is a wasteful number, since it uses less digits than its factorization.

999888888666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61495.

The product of its digits is 41278242816, while the sum is 93.

The spelling of 999888888666 in words is "nine hundred ninety-nine billion, eight hundred eighty-eight million, eight hundred eighty-eight thousand, six hundred sixty-six".