9831981 has 4 divisors (see below), whose sum is σ = 13109312. Its totient is φ = 6554652.

The previous prime is 9831953. The next prime is 9832003. The reversal of 9831981 is 1891389.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 9831981 - 2⁶ = 9831917 is a prime.

It is a super-2 number, since 2×9831981² = 193335700768722, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9831181) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1638661 + ... + 1638666.

It is an arithmetic number, because the mean of its divisors is an integer number (3277328).

Almost surely, 2^9831981 is an apocalyptic number.

It is an amenable number.

9831981 is a deficient number, since it is larger than the sum of its proper divisors (3277331).

9831981 is a wasteful number, since it uses less digits than its factorization.

9831981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3277330.

The product of its digits is 15552, while the sum is 39.

The square root of 9831981 is about 3135.5989858399. The cubic root of 9831981 is about 214.2300274981.

The spelling of 9831981 in words is "nine million, eight hundred thirty-one thousand, nine hundred eighty-one".