399855 has 32 divisors (see below), whose sum is σ = 714240. Its totient is φ = 190080.

The previous prime is 399853. The next prime is 399871. The reversal of 399855 is 558993.

399855 = T₁₉ + T₂₀ + ... + T₁₃₃.

It is not a de Polignac number, because 399855 - 2¹ = 399853 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399851) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6525 + ... + 6585.

It is an arithmetic number, because the mean of its divisors is an integer number (22320).

2³⁹⁹⁸⁵⁵ is an apocalyptic number.

399855 is a deficient number, since it is larger than the sum of its proper divisors (314385).

399855 is a wasteful number, since it uses less digits than its factorization.

399855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111.

The product of its digits is 48600, while the sum is 39.

The square root of 399855 is about 632.3408890780. The cubic root of 399855 is about 73.6717258207.

The spelling of 399855 in words is "three hundred ninety-nine thousand, eight hundred fifty-five".