9999918999 has 48 divisors (see below), whose sum is σ = 16727840064. Its totient is φ = 5638464000.

The previous prime is 9999918989. The next prime is 9999919019. The reversal of 9999918999 is 9998199999.

9999918999 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 9999918999 - 2⁸ = 9999918743 is a prime.

It is a super-2 number, since 2×9999918999² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9999918949) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1989109 + ... + 1994129.

It is an arithmetic number, because the mean of its divisors is an integer number (348496668).

Almost surely, 2^9999918999 is an apocalyptic number.

9999918999 is a deficient number, since it is larger than the sum of its proper divisors (6727921065).

9999918999 is a wasteful number, since it uses less digits than its factorization.

9999918999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5448 (or 5445 counting only the distinct ones).

The product of its digits is 344373768, while the sum is 81.

The square root of 9999918999 is about 99999.5949941799. The cubic root of 9999918999 is about 2154.4288729707.

The spelling of 9999918999 in words is "nine billion, nine hundred ninety-nine million, nine hundred eighteen thousand, nine hundred ninety-nine".