99909990999 has 120 divisors (see below), whose sum is σ = 188808008928. Its totient is φ = 51270278400.

The previous prime is 99909990989. The next prime is 99909991007.

99909990999 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 99909990999 - 2¹² = 99909986903 is a prime.

It is a super-2 number, since 2×99909990999² (a number of 23 digits) contains 22 as substring.

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

99909990999 is a modest number, since divided by 9990999 gives 999 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99909990989) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 10085949 + ... + 10095849.

Almost surely, 2^99909990999 is an apocalyptic number.

99909990999 is a deficient number, since it is larger than the sum of its proper divisors (88898017929).

99909990999 is a wasteful number, since it uses less digits than its factorization.

99909990999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10007 (or 9961 counting only the distinct ones).

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

The spelling of 99909990999 in words is "ninety-nine billion, nine hundred nine million, nine hundred ninety thousand, nine hundred ninety-nine".