90815009 has 2 divisors, whose sum is σ = 90815010. Its totient is φ = 90815008.

The previous prime is 90814991. The next prime is 90815069. The reversal of 90815009 is 90051809.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66064384 + 24750625 = 8128^2 + 4975^2 .

It is an emirp because it is prime and its reverse (90051809) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 90815009 - 2²⁰ = 89766433 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (90815069) 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, 45407504 + 45407505.

It is an arithmetic number, because the mean of its divisors is an integer number (45407505).

Almost surely, 2^90815009 is an apocalyptic number.

It is an amenable number.

90815009 is a deficient number, since it is larger than the sum of its proper divisors (1).

90815009 is an equidigital number, since it uses as much as digits as its factorization.

90815009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3240, while the sum is 32.

The square root of 90815009 is about 9529.6909183876. The cubic root of 90815009 is about 449.4891470334.

The spelling of 90815009 in words is "ninety million, eight hundred fifteen thousand, nine".