399939 has 8 divisors (see below), whose sum is σ = 551760. Its totient is φ = 257376.

The previous prime is 399937. The next prime is 399941. The reversal of 399939 is 939993.

It is an interprime number because it is at equal distance from previous prime (399937) and next prime (399941).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 399939 - 2¹ = 399937 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 399939.

It is not an unprimeable number, because it can be changed into a prime (399937) 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, 2212 + ... + 2385.

It is an arithmetic number, because the mean of its divisors is an integer number (68970).

2³⁹⁹⁹³⁹ is an apocalyptic number.

399939 is a deficient number, since it is larger than the sum of its proper divisors (151821).

399939 is a wasteful number, since it uses less digits than its factorization.

399939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4629.

The product of its digits is 59049, while the sum is 42.

The square root of 399939 is about 632.4073054607. The cubic root of 399939 is about 73.6768843504.

It can be divided in two parts, 3999 and 39, that multiplied together give a triangular number (155961 = T₅₅₈).

The spelling of 399939 in words is "three hundred ninety-nine thousand, nine hundred thirty-nine".