9909961 has 2 divisors, whose sum is σ = 9909962. Its totient is φ = 9909960.

The previous prime is 9909943. The next prime is 9909989. The reversal of 9909961 is 1699099.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9734400 + 175561 = 3120^2 + 419^2 .

It is a cyclic number.

It is not a de Polignac number, because 9909961 - 2⁷ = 9909833 is a prime.

It is not a weakly prime, because it can be changed into another prime (9909901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4954980 + 4954981.

It is an arithmetic number, because the mean of its divisors is an integer number (4954981).

Almost surely, 2^9909961 is an apocalyptic number.

It is an amenable number.

9909961 is a deficient number, since it is larger than the sum of its proper divisors (1).

9909961 is an equidigital number, since it uses as much as digits as its factorization.

9909961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 39366, while the sum is 43.

The square root of 9909961 is about 3148.0090533542. The cubic root of 9909961 is about 214.7949080814.

The spelling of 9909961 in words is "nine million, nine hundred nine thousand, nine hundred sixty-one".