399055 has 4 divisors (see below), whose sum is σ = 478872. Its totient is φ = 319240.

The previous prime is 399043. The next prime is 399059. The reversal of 399055 is 550993.

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

It is not a de Polignac number, because 399055 - 2⁵ = 399023 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399059) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39901 + ... + 39910.

It is an arithmetic number, because the mean of its divisors is an integer number (119718).

2³⁹⁹⁰⁵⁵ is an apocalyptic number.

399055 is a deficient number, since it is larger than the sum of its proper divisors (79817).

399055 is an equidigital number, since it uses as much as digits as its factorization.

399055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79816.

The product of its (nonzero) digits is 6075, while the sum is 31.

The square root of 399055 is about 631.7080021656. The cubic root of 399055 is about 73.6225607231.

The spelling of 399055 in words is "three hundred ninety-nine thousand, fifty-five".