9161809 has 2 divisors, whose sum is σ = 9161810. Its totient is φ = 9161808.

The previous prime is 9161807. The next prime is 9161837. The reversal of 9161809 is 9081619.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8065600 + 1096209 = 2840^2 + 1047^2 .

It is a cyclic number.

It is not a de Polignac number, because 9161809 - 2¹ = 9161807 is a prime.

Together with 9161807, it forms a pair of twin primes.

9161809 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (9161807) 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, 4580904 + 4580905.

It is an arithmetic number, because the mean of its divisors is an integer number (4580905).

Almost surely, 2^9161809 is an apocalyptic number.

It is an amenable number.

9161809 is a deficient number, since it is larger than the sum of its proper divisors (1).

9161809 is an equidigital number, since it uses as much as digits as its factorization.

9161809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 34.

The square root of 9161809 is about 3026.8480305427. The cubic root of 9161809 is about 209.2475642135.

The spelling of 9161809 in words is "nine million, one hundred sixty-one thousand, eight hundred nine".