99999999999 has 12 divisors (see below), whose sum is σ = 144451398000.
Its totient is φ = 66663457344.
The previous prime is 99999999977. The next prime is 100000000003.
99999999999 is nontrivially palindromic in base 10.
It is a Cunningham number, because it is equal to 1011-1.
It is a trimorphic number since its cube, 999999999970000000000299999999999, ends in 99999999999.
It is not a de Polignac number, because 99999999999 - 27 = 99999999871 is a prime.
It is a super-9 number, since 9×999999999999 (a number of 100 digits) contains 999999999 as substring.
It is a nude number because it is divisible by every one of its digits.
99999999999 is a modest number, since divided by 999999 gives 99999 as remainder.
99999999999 is a nontrivial repdigit in base 10.
It is a plaindrome in base 10.
It is a nialpdrome in base 10.
It is a zygodrome in base 10.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (99999999599) by changing a digit.
Being equal to 10×1010-1, it is a generalized Woodall number.
It is a Kaprekar number, because its square (9999999999800000000001) can be partitioned into two parts whose sum is 99999999999.
It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 61779 + ... + 451460.
It is an arithmetic number, because the mean of its divisors is an integer number (12037616500).
Almost surely, 299999999999 is an apocalyptic number.
99999999999 is a deficient number, since it is larger than the sum of its proper divisors (44451398001).
99999999999 is a wasteful number, since it uses less digits than its factorization.
99999999999 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 534894 (or 534891 counting only the distinct ones).
The product of its digits is 31381059609, while the sum is 99.
The spelling of 99999999999 in words is "ninety-nine billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred ninety-nine".