999999099 has 24 divisors (see below), whose sum is σ = 1612408512. Its totient is φ = 591963120.

The previous prime is 999999067. The next prime is 999999103. The reversal of 999999099 is 990999999.

It is not a de Polignac number, because 999999099 - 2⁵ = 999999067 is a prime.

It is not an unprimeable number, because it can be changed into a prime (999999029) 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 23 ways as a sum of consecutive naturals, for example, 113197 + ... + 121710.

It is an arithmetic number, because the mean of its divisors is an integer number (67183688).

Almost surely, 2^999999099 is an apocalyptic number.

999999099 is a gapful number since it is divisible by the number (99) formed by its first and last digit.

999999099 is a deficient number, since it is larger than the sum of its proper divisors (612409413).

999999099 is a wasteful number, since it uses less digits than its factorization.

999999099 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234967 (or 234964 counting only the distinct ones).

The product of its (nonzero) digits is 43046721, while the sum is 72.

The square root of 999999099 is about 31622.7623556197. The cubic root of 999999099 is about 999.9996996666. Note that the first 3 decimals are identical.

The spelling of 999999099 in words is "nine hundred ninety-nine million, nine hundred ninety-nine thousand, ninety-nine".