399090 has 32 divisors (see below), whose sum is σ = 979776. Its totient is φ = 104000.

The previous prime is 399079. The next prime is 399097. The reversal of 399090 is 90993.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (399097) by changing a digit.

399090 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 15 ways as a sum of consecutive naturals, for example, 1465 + ... + 1715.

It is an arithmetic number, because the mean of its divisors is an integer number (30618).

2³⁹⁹⁰⁹⁰ is an apocalyptic number.

399090 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 399090, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (489888).

399090 is an abundant number, since it is smaller than the sum of its proper divisors (580686).

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

399090 is a wasteful number, since it uses less digits than its factorization.

399090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314.

The product of its (nonzero) digits is 2187, while the sum is 30.

The square root of 399090 is about 631.7357042308. The cubic root of 399090 is about 73.6247130700.

The spelling of 399090 in words is "three hundred ninety-nine thousand, ninety".