999999888666666 has 16 divisors (see below), whose sum is σ = 2054053825369824. Its totient is φ = 324324288216144.

The previous prime is 999999888666637. The next prime is 999999888666673. The reversal of 999999888666666 is 666666888999999.

It is a super-2 number, since 2×999999888666666² (a number of 31 digits) contains 22 as substring.

999999888666666 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, 2252252001280 + ... + 2252252001723.

It is an arithmetic number, because the mean of its divisors is an integer number (128378364085614).

Almost surely, 2^{999999888666666} is an apocalyptic number.

999999888666666 is an abundant number, since it is smaller than the sum of its proper divisors (1054053936703158).

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

999999888666666 is a wasteful number, since it uses less digits than its factorization.

999999888666666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4504504003045.

The product of its digits is 12694994583552, while the sum is 114.

The spelling of 999999888666666 in words is "nine hundred ninety-nine trillion, nine hundred ninety-nine billion, eight hundred eighty-eight million, six hundred sixty-six thousand, six hundred sixty-six".