399591 has 12 divisors (see below), whose sum is σ = 597480. Its totient is φ = 257040.

The previous prime is 399587. The next prime is 399601. The reversal of 399591 is 195993.

It is not a de Polignac number, because 399591 - 2² = 399587 is a prime.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399541) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 505 + ... + 1026.

It is an arithmetic number, because the mean of its divisors is an integer number (49790).

2³⁹⁹⁵⁹¹ is an apocalyptic number.

399591 is a deficient number, since it is larger than the sum of its proper divisors (197889).

399591 is a wasteful number, since it uses less digits than its factorization.

399591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1566 (or 1563 counting only the distinct ones).

The product of its digits is 10935, while the sum is 36.

The square root of 399591 is about 632.1321064461. The cubic root of 399591 is about 73.6555085939.

It can be divided in two parts, 399 and 591, that added together give a triangular number (990 = T₄₄).

The spelling of 399591 in words is "three hundred ninety-nine thousand, five hundred ninety-one".