399906 has 24 divisors (see below), whose sum is σ = 933660. Its totient is φ = 122976.

The previous prime is 399899. The next prime is 399911. The reversal of 399906 is 609993.

It can be written as a sum of positive squares in 2 ways, for example, as 349281 + 50625 = 591^2 + 225^2 .

It is an unprimeable number.

399906 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 621 + ... + 1088.

2³⁹⁹⁹⁰⁶ is an apocalyptic number.

399906 is an abundant number, since it is smaller than the sum of its proper divisors (533754).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

399906 is a wasteful number, since it uses less digits than its factorization.

399906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1730 (or 1727 counting only the distinct ones).

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

The square root of 399906 is about 632.3812141422. The cubic root of 399906 is about 73.6748578713.

The spelling of 399906 in words is "three hundred ninety-nine thousand, nine hundred six".