9901609 has 2 divisors, whose sum is σ = 9901610. Its totient is φ = 9901608.

The previous prime is 9901601. The next prime is 9901613. The reversal of 9901609 is 9061099.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9018009 + 883600 = 3003^2 + 940^2 .

It is an emirp because it is prime and its reverse (9061099) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9901609 - 2³ = 9901601 is a prime.

9901609 is a lucky number.

It is equal to p₆₅₈₅₄₆ and since 9901609 and 658546 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 (9901601) 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, 4950804 + 4950805.

It is an arithmetic number, because the mean of its divisors is an integer number (4950805).

Almost surely, 2^9901609 is an apocalyptic number.

It is an amenable number.

9901609 is a deficient number, since it is larger than the sum of its proper divisors (1).

9901609 is an equidigital number, since it uses as much as digits as its factorization.

9901609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4374, while the sum is 34.

The square root of 9901609 is about 3146.6822210068. The cubic root of 9901609 is about 214.7345489038.

The spelling of 9901609 in words is "nine million, nine hundred one thousand, six hundred nine".