9659981 has 2 divisors, whose sum is σ = 9659982. Its totient is φ = 9659980.

The previous prime is 9659963. The next prime is 9659983. The reversal of 9659981 is 1899569.

9659981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9357481 + 302500 = 3059^2 + 550^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9659981 is a prime.

It is a super-2 number, since 2×9659981² = 186630465840722, which contains 22 as substring.

Together with 9659983, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9659983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4829990 + 4829991.

It is an arithmetic number, because the mean of its divisors is an integer number (4829991).

Almost surely, 2^9659981 is an apocalyptic number.

It is an amenable number.

9659981 is a deficient number, since it is larger than the sum of its proper divisors (1).

9659981 is an equidigital number, since it uses as much as digits as its factorization.

9659981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 174960, while the sum is 47.

The square root of 9659981 is about 3108.0509970076. The cubic root of 9659981 is about 212.9734293525.

The spelling of 9659981 in words is "nine million, six hundred fifty-nine thousand, nine hundred eighty-one".