9999900081 has 12 divisors (see below), whose sum is σ = 14448047952. Its totient is φ = 6664870296.

The previous prime is 9999900077. The next prime is 9999900101. The reversal of 9999900081 is 1800099999.

It is not a de Polignac number, because 9999900081 - 2² = 9999900077 is a prime.

It is a super-2 number, since 2×9999900081² (a number of 21 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (9999900481) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 107031 + ... + 177356.

It is an arithmetic number, because the mean of its divisors is an integer number (1204003996).

Almost surely, 2^9999900081 is an apocalyptic number.

It is an amenable number.

9999900081 is a deficient number, since it is larger than the sum of its proper divisors (4448147871).

9999900081 is a wasteful number, since it uses less digits than its factorization.

9999900081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 288300 (or 288297 counting only the distinct ones).

The product of its (nonzero) digits is 472392, while the sum is 54.

The square root of 9999900081 is about 99999.5004037520. The cubic root of 9999900081 is about 2154.4275143760.

The spelling of 9999900081 in words is "nine billion, nine hundred ninety-nine million, nine hundred thousand, eighty-one".