399040 has 56 divisors (see below), whose sum is σ = 1005840. Its totient is φ = 150528.

The previous prime is 399031. The next prime is 399043. The reversal of 399040 is 40993.

399040 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a hoax number, since the sum of its digits (25) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 398996 and 399014.

It is not an unprimeable number, because it can be changed into a prime (399043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9259 + ... + 9301.

2³⁹⁹⁰⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 399040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (502920).

399040 is an abundant number, since it is smaller than the sum of its proper divisors (606800).

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

399040 is a wasteful number, since it uses less digits than its factorization.

399040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89 (or 79 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 25.

The square root of 399040 is about 631.6961294800. The cubic root of 399040 is about 73.6216382503.

The spelling of 399040 in words is "three hundred ninety-nine thousand, forty".