399956 has 6 divisors (see below), whose sum is σ = 699930. Its totient is φ = 199976.

The previous prime is 399953. The next prime is 399979. The reversal of 399956 is 659993.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 211600 + 188356 = 460^2 + 434^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49991 + ... + 49998.

It is an arithmetic number, because the mean of its divisors is an integer number (116655).

2³⁹⁹⁹⁵⁶ is an apocalyptic number.

It is an amenable number.

399956 is a deficient number, since it is larger than the sum of its proper divisors (299974).

399956 is a wasteful number, since it uses less digits than its factorization.

399956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99993 (or 99991 counting only the distinct ones).

The product of its digits is 65610, while the sum is 41.

The square root of 399956 is about 632.4207460228. The cubic root of 399956 is about 73.6779282506.

The spelling of 399956 in words is "three hundred ninety-nine thousand, nine hundred fifty-six".