399870 has 32 divisors (see below), whose sum is σ = 1067040. Its totient is φ = 106560.

The previous prime is 399853. The next prime is 399871. The reversal of 399870 is 78993.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 399870.

It is not an unprimeable number, because it can be changed into a prime (399871) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 471 + ... + 1010.

It is an arithmetic number, because the mean of its divisors is an integer number (33345).

2³⁹⁹⁸⁷⁰ is an apocalyptic number.

399870 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

399870 is an abundant number, since it is smaller than the sum of its proper divisors (667170).

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

399870 is a wasteful number, since it uses less digits than its factorization.

399870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1497 (or 1491 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 36.

The square root of 399870 is about 632.3527496580. The cubic root of 399870 is about 73.6726470397.

The spelling of 399870 in words is "three hundred ninety-nine thousand, eight hundred seventy".