399240 has 48 divisors (see below), whose sum is σ = 1298700. Its totient is φ = 106368.

The previous prime is 399239. The next prime is 399241. The reversal of 399240 is 42993.

It is an interprime number because it is at equal distance from previous prime (399239) and next prime (399241).

It can be written as a sum of positive squares in 2 ways, for example, as 338724 + 60516 = 582^2 + 246^2 .

It is an Ulam number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 399240.

It is not an unprimeable number, because it can be changed into a prime (399241) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 195 + ... + 914.

2³⁹⁹²⁴⁰ is an apocalyptic number.

399240 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 399240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (649350).

399240 is an abundant number, since it is smaller than the sum of its proper divisors (899460).

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

399240 is a wasteful number, since it uses less digits than its factorization.

399240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1126 (or 1119 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 27.

The square root of 399240 is about 631.8544136112. The cubic root of 399240 is about 73.6339359885.

The spelling of 399240 in words is "three hundred ninety-nine thousand, two hundred forty".