9979981 has 8 divisors (see below), whose sum is σ = 10924128. Its totient is φ = 9042000.

The previous prime is 9979967. The next prime is 9979993. The reversal of 9979981 is 1899799.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 9979981 - 2⁹ = 9979469 is a prime.

It is a super-2 number, since 2×9979981² = 199200041520722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9979961) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2271 + ... + 5011.

It is an arithmetic number, because the mean of its divisors is an integer number (1365516).

Almost surely, 2^9979981 is an apocalyptic number.

It is an amenable number.

9979981 is a deficient number, since it is larger than the sum of its proper divisors (944147).

9979981 is a wasteful number, since it uses less digits than its factorization.

9979981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3083.

The product of its digits is 367416, while the sum is 52.

The square root of 9979981 is about 3159.1107926124. The cubic root of 9979981 is about 215.2996075348.

The spelling of 9979981 in words is "nine million, nine hundred seventy-nine thousand, nine hundred eighty-one".