399646 has 16 divisors (see below), whose sum is σ = 680400. Its totient is φ = 174528.

The previous prime is 399643. The next prime is 399647. The reversal of 399646 is 646993.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399643) 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, 90 + ... + 898.

It is an arithmetic number, because the mean of its divisors is an integer number (42525).

2³⁹⁹⁶⁴⁶ is an apocalyptic number.

399646 is a deficient number, since it is larger than the sum of its proper divisors (280754).

399646 is a wasteful number, since it uses less digits than its factorization.

399646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 843.

The product of its digits is 34992, while the sum is 37.

The square root of 399646 is about 632.1756085140. The cubic root of 399646 is about 73.6588877718.

The spelling of 399646 in words is "three hundred ninety-nine thousand, six hundred forty-six".