399379985 has 8 divisors (see below), whose sum is σ = 480987816. Its totient is φ = 318349440.

The previous prime is 399379973. The next prime is 399379991. The reversal of 399379985 is 589973993.

It can be written as a sum of positive squares in 4 ways, for example, as 56685841 + 342694144 = 7529^2 + 18512^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 399379985 - 2¹⁰ = 399378961 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 142796 + ... + 145565.

It is an arithmetic number, because the mean of its divisors is an integer number (60123477).

Almost surely, 2^399379985 is an apocalyptic number.

It is an amenable number.

399379985 is a deficient number, since it is larger than the sum of its proper divisors (81607831).

399379985 is a wasteful number, since it uses less digits than its factorization.

399379985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 288643.

The product of its digits is 16533720, while the sum is 62.

The square root of 399379985 is about 19984.4936137997. The cubic root of 399379985 is about 736.4254103977.

The spelling of 399379985 in words is "three hundred ninety-nine million, three hundred seventy-nine thousand, nine hundred eighty-five".