999999986666665 has 16 divisors (see below), whose sum is σ = 1252323375159168. Its totient is φ = 765126032939136.

The previous prime is 999999986666623. The next prime is 999999986666677. The reversal of 999999986666665 is 566666689999999.

It is a cyclic number.

It is not a de Polignac number, because 999999986666665 - 2²⁵ = 999999953112233 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 518056107 + ... + 519982816.

It is an arithmetic number, because the mean of its divisors is an integer number (78270210947448).

Almost surely, 2^{999999986666665} is an apocalyptic number.

It is an amenable number.

999999986666665 is a deficient number, since it is larger than the sum of its proper divisors (252323388492503).

999999986666665 is a wasteful number, since it uses less digits than its factorization.

999999986666665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1038047328.

The product of its digits is 8926168066560, while the sum is 112.

The spelling of 999999986666665 in words is "nine hundred ninety-nine trillion, nine hundred ninety-nine billion, nine hundred eighty-six million, six hundred sixty-six thousand, six hundred sixty-five".