399555 has 24 divisors (see below), whose sum is σ = 746928. Its totient is φ = 196416.

The previous prime is 399541. The next prime is 399557. The reversal of 399555 is 555993.

399555 is nontrivially palindromic in base 2.

It is not a de Polignac number, because 399555 - 2⁵ = 399523 is a prime.

It is a nude number because it is divisible by every one of its digits.

399555 is a lucky number.

It is a zygodrome in base 2.

It is not an unprimeable number, because it can be changed into a prime (399557) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 244 + ... + 926.

It is an arithmetic number, because the mean of its divisors is an integer number (31122).

2³⁹⁹⁵⁵⁵ is an apocalyptic number.

399555 is a deficient number, since it is larger than the sum of its proper divisors (347373).

399555 is a wasteful number, since it uses less digits than its factorization.

399555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 707 (or 704 counting only the distinct ones).

The product of its digits is 30375, while the sum is 36.

The square root of 399555 is about 632.1036307442. The cubic root of 399555 is about 73.6532966006.

It can be divided in two parts, 399 and 555, that multiplied together give a triangular number (221445 = T₆₆₅).

The spelling of 399555 in words is "three hundred ninety-nine thousand, five hundred fifty-five".