399609 has 12 divisors (see below), whose sum is σ = 659776. Its totient is φ = 228312.

The previous prime is 399601. The next prime is 399613. The reversal of 399609 is 906993.

It is not a de Polignac number, because 399609 - 2³ = 399601 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399601) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3109 + ... + 3234.

2³⁹⁹⁶⁰⁹ is an apocalyptic number.

It is an amenable number.

399609 is a deficient number, since it is larger than the sum of its proper divisors (260167).

399609 is a wasteful number, since it uses less digits than its factorization.

399609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6356 (or 6353 counting only the distinct ones).

The product of its (nonzero) digits is 13122, while the sum is 36.

The square root of 399609 is about 632.1463438161. The cubic root of 399609 is about 73.6566145408.

The spelling of 399609 in words is "three hundred ninety-nine thousand, six hundred nine".