399000 has 128 divisors (see below), whose sum is σ = 1497600. Its totient is φ = 86400.

The previous prime is 398989. The next prime is 399023. The reversal of 399000 is 993.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

399000 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 31 ways as a sum of consecutive naturals, for example, 20991 + ... + 21009.

It is an arithmetic number, because the mean of its divisors is an integer number (11700).

2³⁹⁹⁰⁰⁰ is an apocalyptic number.

399000 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 399000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (748800).

399000 is an abundant number, since it is smaller than the sum of its proper divisors (1098600).

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

399000 is a wasteful number, since it uses less digits than its factorization.

399000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50 (or 36 counting only the distinct ones).

The product of its (nonzero) digits is 243, while the sum is 21.

The square root of 399000 is about 631.6644678942. The cubic root of 399000 is about 73.6191782095.

Adding to 399000 its reverse (993), we get a palindrome (399993).

The spelling of 399000 in words is "three hundred ninety-nine thousand".