385778509 has 2 divisors, whose sum is σ = 385778510. Its totient is φ = 385778508.

The previous prime is 385778479. The next prime is 385778543. The reversal of 385778509 is 905877583.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 243453609 + 142324900 = 15603^2 + 11930^2 .

It is a cyclic number.

It is not a de Polignac number, because 385778509 - 2⁷ = 385778381 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (385779509) 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, 192889254 + 192889255.

It is an arithmetic number, because the mean of its divisors is an integer number (192889255).

Almost surely, 2^385778509 is an apocalyptic number.

It is an amenable number.

385778509 is a deficient number, since it is larger than the sum of its proper divisors (1).

385778509 is an equidigital number, since it uses as much as digits as its factorization.

385778509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2116800, while the sum is 52.

The square root of 385778509 is about 19641.2450980074. The cubic root of 385778509 is about 727.9686499049.

The spelling of 385778509 in words is "three hundred eighty-five million, seven hundred seventy-eight thousand, five hundred nine".