399405 has 8 divisors (see below), whose sum is σ = 639072. Its totient is φ = 213008.

The previous prime is 399403. The next prime is 399409. The reversal of 399405 is 504993.

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

It is a cyclic number.

It is not a de Polignac number, because 399405 - 2¹ = 399403 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399401) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13299 + ... + 13328.

It is an arithmetic number, because the mean of its divisors is an integer number (79884).

2³⁹⁹⁴⁰⁵ is an apocalyptic number.

It is an amenable number.

399405 is a deficient number, since it is larger than the sum of its proper divisors (239667).

399405 is a wasteful number, since it uses less digits than its factorization.

399405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26635.

The product of its (nonzero) digits is 4860, while the sum is 30.

The square root of 399405 is about 631.9849681757. The cubic root of 399405 is about 73.6440785310.

The spelling of 399405 in words is "three hundred ninety-nine thousand, four hundred five".