999909909999 has 192 divisors, whose sum is σ = 2052063756288. Its totient is φ = 452164204800.

The previous prime is 999909909961. The next prime is 999909910007.

999909909999 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 999909909999 - 2⁷ = 999909909871 is a prime.

It is a super-2 number, since 2×999909909999² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999909909899) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 14677714 + ... + 14745680.

It is an arithmetic number, because the mean of its divisors is an integer number (10687832064).

Almost surely, 2^999909909999 is an apocalyptic number.

999909909999 is a gapful number since it is divisible by the number (99) formed by its first and last digit.

999909909999 is an abundant number, since it is smaller than the sum of its proper divisors (1052153846289).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

999909909999 is a wasteful number, since it uses less digits than its factorization.

999909909999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68098 (or 68095 counting only the distinct ones).

The product of its (nonzero) digits is 3486784401, while the sum is 90.

The spelling of 999909909999 in words is "nine hundred ninety-nine billion, nine hundred nine million, nine hundred nine thousand, nine hundred ninety-nine".