99999000809 has 4 divisors (see below), whose sum is σ = 100051276116. Its totient is φ = 99946725504.

The previous prime is 99999000799. The next prime is 99999000811. The reversal of 99999000809 is 90800099999.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 77017350400 + 22981650409 = 277520^2 + 151597^2 .

It is a cyclic number.

It is not a de Polignac number, because 99999000809 - 2⁴ = 99999000793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99999000869) 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 3 ways as a sum of consecutive naturals, for example, 26134784 + ... + 26138609.

It is an arithmetic number, because the mean of its divisors is an integer number (25012819029).

Almost surely, 2^99999000809 is an apocalyptic number.

It is an amenable number.

99999000809 is a deficient number, since it is larger than the sum of its proper divisors (52275307).

99999000809 is a wasteful number, since it uses less digits than its factorization.

99999000809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52275306.

The product of its (nonzero) digits is 4251528, while the sum is 62.

The spelling of 99999000809 in words is "ninety-nine billion, nine hundred ninety-nine million, eight hundred nine", and thus it is an aban number.