990099999 has 12 divisors (see below), whose sum is σ = 1634450896. Its totient is φ = 565771392.

The previous prime is 990099977. The next prime is 990100003. The reversal of 990099999 is 999990099.

It is not a de Polignac number, because 990099999 - 2⁸ = 990099743 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63), and also a Moran number because the ratio is a prime number: 15715873 = 990099999 / (9 + 9 + 0 + 0 + 9 + 9 + 9 + 9 + 9).

It is a Duffinian number.

990099999 is a modest number, since divided by 99999 gives 9900 as remainder.

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 (990095999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7857874 + ... + 7857999.

Almost surely, 2^990099999 is an apocalyptic number.

990099999 is a deficient number, since it is larger than the sum of its proper divisors (644350897).

990099999 is a wasteful number, since it uses less digits than its factorization.

990099999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15715886 (or 15715883 counting only the distinct ones).

The product of its (nonzero) digits is 4782969, while the sum is 63.

The square root of 990099999 is about 31465.8544934028. The cubic root of 990099999 is about 996.6890493712.

The spelling of 990099999 in words is "nine hundred ninety million, ninety-nine thousand, nine hundred ninety-nine".