9999001001 has 16 divisors (see below), whose sum is σ = 11242049280. Its totient is φ = 8814672720.

The previous prime is 9999000983. The next prime is 9999001021. The reversal of 9999001001 is 1001009999.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 9999001001 - 2¹⁰ = 9998999977 is a prime.

It is not an unprimeable number, because it can be changed into a prime (9999001021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10295 + ... + 141788.

It is an arithmetic number, because the mean of its divisors is an integer number (702628080).

Almost surely, 2^9999001001 is an apocalyptic number.

It is an amenable number.

9999001001 is a deficient number, since it is larger than the sum of its proper divisors (1243048279).

9999001001 is a wasteful number, since it uses less digits than its factorization.

9999001001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152276.

The product of its (nonzero) digits is 6561, while the sum is 38.

The square root of 9999001001 is about 99995.0048802439. The cubic root of 9999001001 is about 2154.3629450394.

The spelling of 9999001001 in words is "nine billion, nine hundred ninety-nine million, one thousand, one".