399209585 has 4 divisors (see below), whose sum is σ = 479051508. Its totient is φ = 319367664.

The previous prime is 399209581. The next prime is 399209633. The reversal of 399209585 is 585902993.

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

It can be written as a sum of positive squares in 2 ways, for example, as 260370496 + 138839089 = 16136^2 + 11783^2 .

It is a cyclic number.

It is not a de Polignac number, because 399209585 - 2² = 399209581 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399209581) 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 in 3 ways as a sum of consecutive naturals, for example, 39920954 + ... + 39920963.

It is an arithmetic number, because the mean of its divisors is an integer number (119762877).

Almost surely, 2^399209585 is an apocalyptic number.

It is an amenable number.

399209585 is a deficient number, since it is larger than the sum of its proper divisors (79841923).

399209585 is an equidigital number, since it uses as much as digits as its factorization.

399209585 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79841922.

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

The square root of 399209585 is about 19980.2298535327. The cubic root of 399209585 is about 736.3206607477.

The spelling of 399209585 in words is "three hundred ninety-nine million, two hundred nine thousand, five hundred eighty-five".