9981139021 has 16 divisors (see below), whose sum is σ = 11573509248. Its totient is φ = 8430912000.

The previous prime is 9981139001. The next prime is 9981139079. The reversal of 9981139021 is 1209311899.

It is not a de Polignac number, because 9981139021 - 2⁵ = 9981138989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9981139001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 211561 + ... + 254401.

It is an arithmetic number, because the mean of its divisors is an integer number (723344328).

Almost surely, 2^9981139021 is an apocalyptic number.

It is an amenable number.

9981139021 is a deficient number, since it is larger than the sum of its proper divisors (1592370227).

9981139021 is a wasteful number, since it uses less digits than its factorization.

9981139021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43332.

The product of its (nonzero) digits is 34992, while the sum is 43.

The square root of 9981139021 is about 99905.6505959498. The cubic root of 9981139021 is about 2153.0793459890.

The spelling of 9981139021 in words is "nine billion, nine hundred eighty-one million, one hundred thirty-nine thousand, twenty-one".