399685 has 24 divisors (see below), whose sum is σ = 579744. Its totient is φ = 262080.

The previous prime is 399677. The next prime is 399689. The reversal of 399685 is 586993.

399685 is nontrivially palindromic in base 12.

It is not a de Polignac number, because 399685 - 2³ = 399677 is a prime.

Its product of digits (58320) is a multiple of the sum of its prime divisors (72).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399689) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9274 + ... + 9316.

It is an arithmetic number, because the mean of its divisors is an integer number (24156).

2³⁹⁹⁶⁸⁵ is an apocalyptic number.

It is an amenable number.

399685 is a deficient number, since it is larger than the sum of its proper divisors (180059).

399685 is a wasteful number, since it uses less digits than its factorization.

399685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85 (or 72 counting only the distinct ones).

The product of its digits is 58320, while the sum is 40.

The square root of 399685 is about 632.2064536210. The cubic root of 399685 is about 73.6612837282.

The spelling of 399685 in words is "three hundred ninety-nine thousand, six hundred eighty-five".