399988 has 18 divisors (see below), whose sum is σ = 741426. Its totient is φ = 188784.

The previous prime is 399983. The next prime is 399989. The reversal of 399988 is 889993.

It can be written as a sum of positive squares in only one way, i.e., 283024 + 116964 = 532^2 + 342^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399983) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1306 + ... + 1582.

2³⁹⁹⁹⁸⁸ is an apocalyptic number.

399988 is a gapful number since it is divisible by the number (38) formed by its first and last digit.

It is an amenable number.

399988 is a deficient number, since it is larger than the sum of its proper divisors (341438).

399988 is a wasteful number, since it uses less digits than its factorization.

399988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319 (or 298 counting only the distinct ones).

The product of its digits is 139968, while the sum is 46.

The square root of 399988 is about 632.4460451295. The cubic root of 399988 is about 73.6798931591.

The spelling of 399988 in words is "three hundred ninety-nine thousand, nine hundred eighty-eight".