399009 has 12 divisors (see below), whose sum is σ = 576816. Its totient is φ = 245232.

The previous prime is 398989. The next prime is 399023. The reversal of 399009 is 900993.

It is not a de Polignac number, because 399009 - 2⁵ = 398977 is a prime.

It is not an unprimeable number, because it can be changed into a prime (399059) 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, 114 + ... + 900.

It is an arithmetic number, because the mean of its divisors is an integer number (48068).

2³⁹⁹⁰⁰⁹ is an apocalyptic number.

399009 is a gapful number since it is divisible by the number (39) formed by its first and last digit.

399009 is the 338-th nonagonal number.

It is an amenable number.

399009 is a deficient number, since it is larger than the sum of its proper divisors (177807).

399009 is a wasteful number, since it uses less digits than its factorization.

399009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 816 (or 803 counting only the distinct ones).

The product of its (nonzero) digits is 2187, while the sum is 30.

The square root of 399009 is about 631.6715918893. The cubic root of 399009 is about 73.6197317330.

The spelling of 399009 in words is "three hundred ninety-nine thousand, nine".