399331 has 4 divisors (see below), whose sum is σ = 403312. Its totient is φ = 395352.

The previous prime is 399283. The next prime is 399353. The reversal of 399331 is 133993.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 399331 - 2⁹ = 398819 is a prime.

It is a super-2 number, since 2×399331² = 318930495122, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 399331.

It is not an unprimeable number, because it can be changed into a prime (399391) 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, 1836 + ... + 2041.

It is an arithmetic number, because the mean of its divisors is an integer number (100828).

2³⁹⁹³³¹ is an apocalyptic number.

399331 is a deficient number, since it is larger than the sum of its proper divisors (3981).

399331 is a wasteful number, since it uses less digits than its factorization.

399331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3980.

The product of its digits is 2187, while the sum is 28.

The square root of 399331 is about 631.9264197674. The cubic root of 399331 is about 73.6395300999.

The spelling of 399331 in words is "three hundred ninety-nine thousand, three hundred thirty-one".