385217309 has 2 divisors, whose sum is σ = 385217310. Its totient is φ = 385217308.

The previous prime is 385217281. The next prime is 385217321. The reversal of 385217309 is 903712583.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 214183225 + 171034084 = 14635^2 + 13078^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-385217309 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (385217369) 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, 192608654 + 192608655.

It is an arithmetic number, because the mean of its divisors is an integer number (192608655).

Almost surely, 2^385217309 is an apocalyptic number.

It is an amenable number.

385217309 is a deficient number, since it is larger than the sum of its proper divisors (1).

385217309 is an equidigital number, since it uses as much as digits as its factorization.

385217309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 45360, while the sum is 38.

The square root of 385217309 is about 19626.9536352435. The cubic root of 385217309 is about 727.6154815635.

The spelling of 385217309 in words is "three hundred eighty-five million, two hundred seventeen thousand, three hundred nine".