9897809 has 2 divisors, whose sum is σ = 9897810. Its totient is φ = 9897808.

The previous prime is 9897793. The next prime is 9897829. The reversal of 9897809 is 9087989.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7102225 + 2795584 = 2665^2 + 1672^2 .

It is a cyclic number.

It is not a de Polignac number, because 9897809 - 2⁴ = 9897793 is a prime.

It is not a weakly prime, because it can be changed into another prime (9897829) 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, 4948904 + 4948905.

It is an arithmetic number, because the mean of its divisors is an integer number (4948905).

Almost surely, 2^9897809 is an apocalyptic number.

It is an amenable number.

9897809 is a deficient number, since it is larger than the sum of its proper divisors (1).

9897809 is an equidigital number, since it uses as much as digits as its factorization.

9897809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 326592, while the sum is 50.

The square root of 9897809 is about 3146.0783524890. The cubic root of 9897809 is about 214.7070753995.

The spelling of 9897809 in words is "nine million, eight hundred ninety-seven thousand, eight hundred nine".