1808668409 has 2 divisors, whose sum is σ = 1808668410. Its totient is φ = 1808668408.

The previous prime is 1808668397. The next prime is 1808668441. The reversal of 1808668409 is 9048668081.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1589776384 + 218892025 = 39872^2 + 14795^2 .

It is a cyclic number.

It is not a de Polignac number, because 1808668409 - 2²⁰ = 1807619833 is a prime.

It is not a weakly prime, because it can be changed into another prime (1808661409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 904334204 + 904334205.

It is an arithmetic number, because the mean of its divisors is an integer number (904334205).

Almost surely, 2^1808668409 is an apocalyptic number.

It is an amenable number.

1808668409 is a deficient number, since it is larger than the sum of its proper divisors (1).

1808668409 is an equidigital number, since it uses as much as digits as its factorization.

1808668409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 663552, while the sum is 50.

The square root of 1808668409 is about 42528.4423533240. The cubic root of 1808668409 is about 1218.3899771159.

The spelling of 1808668409 in words is "one billion, eight hundred eight million, six hundred sixty-eight thousand, four hundred nine".