999665555544111 has 16 divisors (see below), whose sum is σ = 1337920003353600. Its totient is φ = 663927693213408.

The previous prime is 999665555544037. The next prime is 999665555544137. The reversal of 999665555544111 is 111445555566999.

It is not a de Polignac number, because 999665555544111 - 2⁷ = 999665555543983 is a prime.

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999665555544311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is an upside-down number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22016631 + ... + 49840376.

It is an arithmetic number, because the mean of its divisors is an integer number (83620000209600).

Almost surely, 2^{999665555544111} is an apocalyptic number.

999665555544111 is a deficient number, since it is larger than the sum of its proper divisors (338254447809489).

999665555544111 is a wasteful number, since it uses less digits than its factorization.

999665555544111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71874518.

The product of its digits is 1312200000, while the sum is 75.

The spelling of 999665555544111 in words is "nine hundred ninety-nine trillion, six hundred sixty-five billion, five hundred fifty-five million, five hundred forty-four thousand, one hundred eleven".