999990000000 has 768 divisors, whose sum is σ = 3698287407360. Its totient is φ = 259200000000.

The previous prime is 999989999993. The next prime is 999990000017. The reversal of 999990000000 is 99999.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3689999865 + ... + 3690000135.

It is an arithmetic number, because the mean of its divisors is an integer number (4815478395).

Almost surely, 2^999990000000 is an apocalyptic number.

999990000000 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 999990000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1849143703680).

999990000000 is an abundant number, since it is smaller than the sum of its proper divisors (2698297407360).

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

999990000000 is an frugal number, since it uses more digits than its factorization.

999990000000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 367 (or 322 counting only the distinct ones).

The product of its (nonzero) digits is 59049, while the sum is 45.

Adding to 999990000000 its reverse (99999), we get a palindrome (999990099999).

999990000000 divided by its reverse (99999) gives a 7-th power (10000000 = 10⁷).

The spelling of 999990000000 in words is "nine hundred ninety-nine billion, nine hundred ninety million", and thus it is an aban number.