9641981 has 2 divisors, whose sum is σ = 9641982. Its totient is φ = 9641980.

The previous prime is 9641971. The next prime is 9641999. The reversal of 9641981 is 1891469.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8213956 + 1428025 = 2866^2 + 1195^2 .

It is a cyclic number.

It is not a de Polignac number, because 9641981 - 2⁶ = 9641917 is a prime.

It is a super-2 number, since 2×9641981² = 185935595208722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9641921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4820990 + 4820991.

It is an arithmetic number, because the mean of its divisors is an integer number (4820991).

Almost surely, 2^9641981 is an apocalyptic number.

It is an amenable number.

9641981 is a deficient number, since it is larger than the sum of its proper divisors (1).

9641981 is an equidigital number, since it uses as much as digits as its factorization.

9641981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15552, while the sum is 38.

The square root of 9641981 is about 3105.1539414335. The cubic root of 9641981 is about 212.8410652112.

The spelling of 9641981 in words is "nine million, six hundred forty-one thousand, nine hundred eighty-one".