9999998881 has 4 divisors (see below), whose sum is σ = 10091742100. Its totient is φ = 9908255664.

The previous prime is 9999998867. The next prime is 9999999001. The reversal of 9999998881 is 1888999999.

9999998881 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6661008225 + 3338990656 = 81615^2 + 57784^2 .

It is a cyclic number.

It is not a de Polignac number, because 9999998881 - 2¹⁵ = 9999966113 is a prime.

It is a super-2 number, since 2×9999998881² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (9999998821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45871446 + ... + 45871663.

It is an arithmetic number, because the mean of its divisors is an integer number (2522935525).

Almost surely, 2^9999998881 is an apocalyptic number.

It is an amenable number.

9999998881 is a deficient number, since it is larger than the sum of its proper divisors (91743219).

9999998881 is a wasteful number, since it uses less digits than its factorization.

9999998881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91743218.

The product of its digits is 272097792, while the sum is 79.

The square root of 9999998881 is about 99999.9944049998. The cubic root of 9999998881 is about 2154.4346096715.

The spelling of 9999998881 in words is "nine billion, nine hundred ninety-nine million, nine hundred ninety-eight thousand, eight hundred eighty-one".