399439585 has 4 divisors (see below), whose sum is σ = 479327508. Its totient is φ = 319551664.

The previous prime is 399439561. The next prime is 399439609. The reversal of 399439585 is 585934993.

It is a happy number.

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 (399439561) and next prime (399439609).

It can be written as a sum of positive squares in 2 ways, for example, as 77739489 + 321700096 = 8817^2 + 17936^2 .

It is a cyclic number.

It is not a de Polignac number, because 399439585 - 2¹⁷ = 399308513 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 39943954 + ... + 39943963.

It is an arithmetic number, because the mean of its divisors is an integer number (119831877).

Almost surely, 2^399439585 is an apocalyptic number.

It is an amenable number.

399439585 is a deficient number, since it is larger than the sum of its proper divisors (79887923).

399439585 is an equidigital number, since it uses as much as digits as its factorization.

399439585 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79887922.

The product of its digits is 5248800, while the sum is 55.

The square root of 399439585 is about 19985.9847142942. The cubic root of 399439585 is about 736.4620411529.

The spelling of 399439585 in words is "three hundred ninety-nine million, four hundred thirty-nine thousand, five hundred eighty-five".