9806561 has 2 divisors, whose sum is σ = 9806562. Its totient is φ = 9806560.

The previous prime is 9806557. The next prime is 9806581. The reversal of 9806561 is 1656089.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9728161 + 78400 = 3119^2 + 280^2 .

It is a cyclic number.

It is not a de Polignac number, because 9806561 - 2² = 9806557 is a prime.

It is equal to p₆₅₂₆₈₈ and since 9806561 and 652688 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (9806581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4903280 + 4903281.

It is an arithmetic number, because the mean of its divisors is an integer number (4903281).

Almost surely, 2^9806561 is an apocalyptic number.

It is an amenable number.

9806561 is a deficient number, since it is larger than the sum of its proper divisors (1).

9806561 is an equidigital number, since it uses as much as digits as its factorization.

9806561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 35.

The square root of 9806561 is about 3131.5429104517. The cubic root of 9806561 is about 214.0452418395.

The spelling of 9806561 in words is "nine million, eight hundred six thousand, five hundred sixty-one".