999991111166666 has 64 divisors (see below), whose sum is σ = 1556446748032512. Its totient is φ = 481527244800000.

The previous prime is 999991111166633. The next prime is 999991111166687. The reversal of 999991111166666 is 666661111199999.

999991111166666 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 polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7159036346 + ... + 7159176026.

It is an arithmetic number, because the mean of its divisors is an integer number (24319480438008).

Almost surely, 2^{999991111166666} is an apocalyptic number.

999991111166666 is a deficient number, since it is larger than the sum of its proper divisors (556455636865846).

999991111166666 is a wasteful number, since it uses less digits than its factorization.

999991111166666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142959.

The product of its digits is 459165024, while the sum is 80.

The spelling of 999991111166666 in words is "nine hundred ninety-nine trillion, nine hundred ninety-one billion, one hundred eleven million, one hundred sixty-six thousand, six hundred sixty-six".