9999099999 has 40 divisors (see below), whose sum is σ = 17969255040. Its totient is φ = 5413040784.

The previous prime is 9999099991. The next prime is 9999100009. The reversal of 9999099999 is 9999909999.

It is not a de Polignac number, because 9999099999 - 2³ = 9999099991 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (81).

9999099999 is a modest number, since divided by 99999 gives 99990 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9999099991) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 453309 + ... + 474854.

It is an arithmetic number, because the mean of its divisors is an integer number (449231376).

Almost surely, 2^9999099999 is an apocalyptic number.

9999099999 is a deficient number, since it is larger than the sum of its proper divisors (7970155041).

9999099999 is a wasteful number, since it uses less digits than its factorization.

9999099999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 928201 (or 928192 counting only the distinct ones).

The product of its (nonzero) digits is 387420489, while the sum is 81.

The square root of 9999099999 is about 99995.4998937452. The cubic root of 9999099999 is about 2154.3700549803.

Subtracting 9999099999 from its reverse (9999909999), we obtain a 4-th power (810000 = 30⁴).

The spelling of 9999099999 in words is "nine billion, nine hundred ninety-nine million, ninety-nine thousand, nine hundred ninety-nine".