999966888996666 has 16 divisors (see below), whose sum is σ = 2068897011717600. Its totient is φ = 321828424044848.

The previous prime is 999966888996619. The next prime is 999966888996689. The reversal of 999966888996666 is 666699888669999.

999966888996666 is a strobogrammatic number because it is the same when read upside-down.

It is a zygodrome in base 10.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2873468071656 + ... + 2873468072003.

It is an arithmetic number, because the mean of its divisors is an integer number (129306063232350).

Almost surely, 2^{999966888996666} is an apocalyptic number.

999966888996666 is an abundant number, since it is smaller than the sum of its proper divisors (1068930122720934).

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

999966888996666 is a wasteful number, since it uses less digits than its factorization.

999966888996666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5746936143693.

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

The spelling of 999966888996666 in words is "nine hundred ninety-nine trillion, nine hundred sixty-six billion, eight hundred eighty-eight million, nine hundred ninety-six thousand, six hundred sixty-six".