385931809 has 4 divisors (see below), whose sum is σ = 386247060. Its totient is φ = 385616560.

The previous prime is 385931779. The next prime is 385931839. The reversal of 385931809 is 908139583.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (385931779) and next prime (385931839).

It can be written as a sum of positive squares in 2 ways, for example, as 303630625 + 82301184 = 17425^2 + 9072^2 .

It is a cyclic number.

It is not a de Polignac number, because 385931809 - 2¹³ = 385923617 is a prime.

It is a super-2 number, since 2×385931809² = 297886722396024962, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (385931839) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 155782 + ... + 158239.

It is an arithmetic number, because the mean of its divisors is an integer number (96561765).

Almost surely, 2^385931809 is an apocalyptic number.

It is an amenable number.

385931809 is a deficient number, since it is larger than the sum of its proper divisors (315251).

385931809 is a wasteful number, since it uses less digits than its factorization.

385931809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 315250.

The product of its (nonzero) digits is 233280, while the sum is 46.

The square root of 385931809 is about 19645.1472124797. The cubic root of 385931809 is about 728.0650634449.

The spelling of 385931809 in words is "three hundred eighty-five million, nine hundred thirty-one thousand, eight hundred nine".