999999000999 has 40 divisors (see below), whose sum is σ = 1624446437328. Its totient is φ = 610492204800.

The previous prime is 999999000961. The next prime is 999999001013. The reversal of 999999000999 is 999000999999.

It is not a de Polignac number, because 999999000999 - 2⁸ = 999999000743 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (81).

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 (999999000929) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 9762777 + ... + 9864674.

Almost surely, 2^999999000999 is an apocalyptic number.

999999000999 is a deficient number, since it is larger than the sum of its proper divisors (624447436329).

999999000999 is a wasteful number, since it uses less digits than its factorization.

999999000999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19627517 (or 19627508 counting only the distinct ones).

The product of its (nonzero) digits is 387420489, while the sum is 81.

It can be divided in two parts, 999999000 and 999, that added together give a palindrome (999999999).

The spelling of 999999000999 in words is "nine hundred ninety-nine billion, nine hundred ninety-nine million, nine hundred ninety-nine", and thus it is an aban number.