9998888666 has 16 divisors (see below), whose sum is σ = 16158105600. Its totient is φ = 4613141808.

The previous prime is 9998888659. The next prime is 9998888671. The reversal of 9998888666 is 6668888999.

9998888666 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 an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26 + ... + 141413.

It is an arithmetic number, because the mean of its divisors is an integer number (1009881600).

Almost surely, 2^9998888666 is an apocalyptic number.

9998888666 is a deficient number, since it is larger than the sum of its proper divisors (6159216934).

9998888666 is a wasteful number, since it uses less digits than its factorization.

9998888666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144173.

The product of its digits is 644972544, while the sum is 77.

The square root of 9998888666 is about 99994.4431756085. The cubic root of 9998888666 is about 2154.3548771911.

The spelling of 9998888666 in words is "nine billion, nine hundred ninety-eight million, eight hundred eighty-eight thousand, six hundred sixty-six".