99009999 has 16 divisors (see below), whose sum is σ = 160016640. Its totient is φ = 60005880.

The previous prime is 99009991. The next prime is 99010019. The reversal of 99009999 is 99990099.

It is not a de Polignac number, because 99009999 - 2³ = 99009991 is a prime.

99009999 is a modest number, since divided by 9999 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 (99009991) 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 15 ways as a sum of consecutive naturals, for example, 166387 + ... + 166980.

It is an arithmetic number, because the mean of its divisors is an integer number (10001040).

Almost surely, 2^99009999 is an apocalyptic number.

99009999 is a gapful number since it is divisible by the number (99) formed by its first and last digit.

99009999 is a deficient number, since it is larger than the sum of its proper divisors (61006641).

99009999 is a wasteful number, since it uses less digits than its factorization.

99009999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333387 (or 333381 counting only the distinct ones).

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

The square root of 99009999 is about 9950.3768270352. The cubic root of 99009999 is about 462.6220748128.

Subtracting 99009999 from its reverse (99990099), we obtain a square (980100 = 990²).

The spelling of 99009999 in words is "ninety-nine million, nine thousand, nine hundred ninety-nine".