399456 has 72 divisors (see below), whose sum is σ = 1212120. Its totient is φ = 124416.

The previous prime is 399439. The next prime is 399473. The reversal of 399456 is 654993.

399456 = 21³ + 22³ + ... + 36³.

It is an interprime number because it is at equal distance from previous prime (399439) and next prime (399473).

It is a tau number, because it is divible by the number of its divisors (72).

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

Its product of digits (29160) is a multiple of the sum of its prime factors (108).

It is a zygodrome in base 2.

It is a self number, because there is not a number n which added to its sum of digits gives 399456.

It is a congruent number.

It is an unprimeable number.

399456 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 11 ways as a sum of consecutive naturals, for example, 5436 + ... + 5508.

It is an arithmetic number, because the mean of its divisors is an integer number (16835).

2³⁹⁹⁴⁵⁶ is an apocalyptic number.

399456 is a gapful number since it is divisible by the number (36) 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 399456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (606060).

399456 is an abundant number, since it is smaller than the sum of its proper divisors (812664).

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

399456 is a wasteful number, since it uses less digits than its factorization.

399456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108 (or 97 counting only the distinct ones).

The product of its digits is 29160, while the sum is 36.

The square root of 399456 is about 632.0253159487. The cubic root of 399456 is about 73.6472129336.

The spelling of 399456 in words is "three hundred ninety-nine thousand, four hundred fifty-six".