999999000000 has 3136 divisors, whose sum is σ = 5067235138560. Its totient is φ = 186624000000.

The previous prime is 999998999999. The next prime is 999999000001. The reversal of 999999000000 is 999999.

It is an interprime number because it is at equal distance from previous prime (999998999999) and next prime (999999000001).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

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 (999999000001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 447 ways as a sum of consecutive naturals, for example, 27026999982 + ... + 27027000018.

Almost surely, 2^999999000000 is an apocalyptic number.

999999000000 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is a pronic number, being equal to 999999×1000000.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 999999000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2533617569280).

999999000000 is an abundant number, since it is smaller than the sum of its proper divisors (4067236138560).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

999999000000 is a wasteful number, since it uses less digits than its factorization.

999999000000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119 (or 78 counting only the distinct ones).

The product of its (nonzero) digits is 531441, while the sum is 54.

Adding to 999999000000 its reverse (999999), we get a palindrome (999999999999).

Subtracting from 999999000000 its reverse (999999), we obtain a square (999998000001 = 999999²).

999999000000 divided by its reverse (999999) gives a 6-th power (1000000 = 10⁶).

It can be divided in two parts, 999 and 999000000, that multiplied together give a square (998001000000 = 999000²).

The spelling of 999999000000 in words is "nine hundred ninety-nine billion, nine hundred ninety-nine million", and thus it is an aban number.