9919881 has 32 divisors (see below), whose sum is σ = 15772800. Its totient is φ = 6143040.

The previous prime is 9919853. The next prime is 9919883. The reversal of 9919881 is 1889199.

It is not a de Polignac number, because 9919881 - 2⁵ = 9919849 is a prime.

It is a super-2 number, since 2×9919881² = 196808078108322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (9919883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 31135 + ... + 31451.

It is an arithmetic number, because the mean of its divisors is an integer number (492900).

Almost surely, 2^9919881 is an apocalyptic number.

It is an amenable number.

9919881 is a deficient number, since it is larger than the sum of its proper divisors (5852919).

9919881 is a wasteful number, since it uses less digits than its factorization.

9919881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 406 (or 400 counting only the distinct ones).

The product of its digits is 46656, while the sum is 45.

The square root of 9919881 is about 3149.5842582792. The cubic root of 9919881 is about 214.8665550135.

The spelling of 9919881 in words is "nine million, nine hundred nineteen thousand, eight hundred eighty-one".