9663981 has 4 divisors (see below), whose sum is σ = 12885312. Its totient is φ = 6442652.

The previous prime is 9663977. The next prime is 9664003. The reversal of 9663981 is 1893669.

9663981 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1893669 = 3 ⋅631223.

It is a cyclic number.

It is not a de Polignac number, because 9663981 - 2² = 9663977 is a prime.

It is a super-2 number, since 2×9663981² = 186785057536722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9663911) 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, 1610661 + ... + 1610666.

It is an arithmetic number, because the mean of its divisors is an integer number (3221328).

Almost surely, 2^9663981 is an apocalyptic number.

It is an amenable number.

9663981 is a deficient number, since it is larger than the sum of its proper divisors (3221331).

9663981 is a wasteful number, since it uses less digits than its factorization.

9663981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3221330.

The product of its digits is 69984, while the sum is 42.

The square root of 9663981 is about 3108.6944204923. The cubic root of 9663981 is about 213.0028212723.

The spelling of 9663981 in words is "nine million, six hundred sixty-three thousand, nine hundred eighty-one".