9909990899 has 4 divisors (see below), whose sum is σ = 9910198536. Its totient is φ = 9909783264.

The previous prime is 9909990889. The next prime is 9909990953. The reversal of 9909990899 is 9980999099.

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

It is a cyclic number.

It is not a de Polignac number, because 9909990899 - 2¹² = 9909986803 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9909990869) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7712 + ... + 140994.

It is an arithmetic number, because the mean of its divisors is an integer number (2477549634).

Almost surely, 2^9909990899 is an apocalyptic number.

9909990899 is a deficient number, since it is larger than the sum of its proper divisors (207637).

9909990899 is a wasteful number, since it uses less digits than its factorization.

9909990899 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207636.

The product of its (nonzero) digits is 38263752, while the sum is 71.

The square root of 9909990899 is about 99548.9372067829. The cubic root of 9909990899 is about 2147.9512409794.

The spelling of 9909990899 in words is "nine billion, nine hundred nine million, nine hundred ninety thousand, eight hundred ninety-nine".