8991981009 has 12 divisors (see below), whose sum is σ = 14169182352. Its totient is φ = 5449685400.

The previous prime is 8991980971. The next prime is 8991981013. The reversal of 8991981009 is 9001891998.

It is not a de Polignac number, because 8991981009 - 2¹³ = 8991972817 is a prime.

It is not an unprimeable number, because it can be changed into a prime (8991981709) 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, 45413947 + ... + 45414144.

It is an arithmetic number, because the mean of its divisors is an integer number (1180765196).

Almost surely, 2^8991981009 is an apocalyptic number.

It is an amenable number.

8991981009 is a deficient number, since it is larger than the sum of its proper divisors (5177201343).

8991981009 is a wasteful number, since it uses less digits than its factorization.

8991981009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90828108 (or 90828105 counting only the distinct ones).

The product of its (nonzero) digits is 419904, while the sum is 54.

The square root of 8991981009 is about 94826.0565931116. The cubic root of 8991981009 is about 2079.4658552772.

The spelling of 8991981009 in words is "eight billion, nine hundred ninety-one million, nine hundred eighty-one thousand, nine".