399638 has 4 divisors (see below), whose sum is σ = 599460. Its totient is φ = 199818.

The previous prime is 399617. The next prime is 399643. The reversal of 399638 is 836993.

It is a happy number.

399638 is nontrivially palindromic in base 16.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99908 + ... + 99911.

It is an arithmetic number, because the mean of its divisors is an integer number (149865).

2³⁹⁹⁶³⁸ is an apocalyptic number.

399638 is a deficient number, since it is larger than the sum of its proper divisors (199822).

399638 is a wasteful number, since it uses less digits than its factorization.

399638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199821.

The product of its digits is 34992, while the sum is 38.

The square root of 399638 is about 632.1692811265. The cubic root of 399638 is about 73.6583962743.

The spelling of 399638 in words is "three hundred ninety-nine thousand, six hundred thirty-eight".