399980 has 24 divisors (see below), whose sum is σ = 960288. Its totient is φ = 137088.

The previous prime is 399979. The next prime is 399983. The reversal of 399980 is 89993.

399980 is an esthetic number in base 6, because in such base its adjacent digits differ by 1.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is a zygodrome in base 13.

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 7 ways as a sum of consecutive naturals, for example, 1289 + ... + 1568.

It is an arithmetic number, because the mean of its divisors is an integer number (40012).

2³⁹⁹⁹⁸⁰ is an apocalyptic number.

It is an amenable number.

399980 is an abundant number, since it is smaller than the sum of its proper divisors (560308).

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

399980 is a wasteful number, since it uses less digits than its factorization.

399980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2873 (or 2871 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 38.

The square root of 399980 is about 632.4397204477. The cubic root of 399980 is about 73.6794019418.

The spelling of 399980 in words is "three hundred ninety-nine thousand, nine hundred eighty".