399056 has 30 divisors (see below), whose sum is σ = 901170. Its totient is φ = 170688.

The previous prime is 399043. The next prime is 399059. The reversal of 399056 is 650993.

It can be written as a sum of positive squares in only one way, i.e., 379456 + 19600 = 616^2 + 140^2 .

It is a super-2 number, since 2×399056² = 318491382272, which contains 22 as substring.

It is a congruent number.

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

399056 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 530 + ... + 1038.

It is an arithmetic number, because the mean of its divisors is an integer number (30039).

2³⁹⁹⁰⁵⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 399056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (450585).

399056 is an abundant number, since it is smaller than the sum of its proper divisors (502114).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

399056 is a wasteful number, since it uses less digits than its factorization.

399056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 531 (or 518 counting only the distinct ones).

The product of its (nonzero) digits is 7290, while the sum is 32.

The square root of 399056 is about 631.7087936700. The cubic root of 399056 is about 73.6226222205.

The spelling of 399056 in words is "three hundred ninety-nine thousand, fifty-six".