999991111166633 has 2 divisors, whose sum is σ = 999991111166634. Its totient is φ = 999991111166632.

The previous prime is 999991111166623. The next prime is 999991111166687. The reversal of 999991111166633 is 336661111199999.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 573108900934249 + 426882210232384 = 23939693^2 + 20661128^2 .

It is an emirp because it is prime and its reverse (336661111199999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 999991111166633 - 2⁶ = 999991111166569 is a prime.

It is a zygodrome in base 10.

It is not a weakly prime, because it can be changed into another prime (999991111166623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499995555583316 + 499995555583317.

It is an arithmetic number, because the mean of its divisors is an integer number (499995555583317).

Almost surely, 2^{999991111166633} is an apocalyptic number.

It is an amenable number.

999991111166633 is a deficient number, since it is larger than the sum of its proper divisors (1).

999991111166633 is an equidigital number, since it uses as much as digits as its factorization.

999991111166633 is an evil number, because the sum of its binary digits is even.

The product of its digits is 114791256, while the sum is 74.

The spelling of 999991111166633 in words is "nine hundred ninety-nine trillion, nine hundred ninety-one billion, one hundred eleven million, one hundred sixty-six thousand, six hundred thirty-three".