3985209509 has 2 divisors, whose sum is σ = 3985209510. Its totient is φ = 3985209508.

The previous prime is 3985209491. The next prime is 3985209521. The reversal of 3985209509 is 9059025893.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3323176609 + 662032900 = 57647^2 + 25730^2 .

It is a cyclic number.

It is not a de Polignac number, because 3985209509 - 2⁸ = 3985209253 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3985200509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1992604754 + 1992604755.

It is an arithmetic number, because the mean of its divisors is an integer number (1992604755).

Almost surely, 2^3985209509 is an apocalyptic number.

It is an amenable number.

3985209509 is a deficient number, since it is larger than the sum of its proper divisors (1).

3985209509 is an equidigital number, since it uses as much as digits as its factorization.

3985209509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 874800, while the sum is 50.

The square root of 3985209509 is about 63128.5158149627. The cubic root of 3985209509 is about 1585.4420987428.

The spelling of 3985209509 in words is "three billion, nine hundred eighty-five million, two hundred nine thousand, five hundred nine".