399564 has 36 divisors (see below), whose sum is σ = 1102920. Its totient is φ = 120960.

The previous prime is 399557. The next prime is 399571. The reversal of 399564 is 465993.

399564 is a `hidden beast` number, since 3 + 99 + 564 = 666.

It is an interprime number because it is at equal distance from previous prime (399557) and next prime (399571).

It is a tau number, because it is divible by the number of its divisors (36).

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

It is a zygodrome in base 2.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 399564.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 109 + ... + 900.

2³⁹⁹⁵⁶⁴ 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 399564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (551460).

399564 is an abundant number, since it is smaller than the sum of its proper divisors (703356).

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

399564 is a wasteful number, since it uses less digits than its factorization.

399564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1030 (or 1025 counting only the distinct ones).

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

The square root of 399564 is about 632.1107497899. The cubic root of 399564 is about 73.6538496114.

The spelling of 399564 in words is "three hundred ninety-nine thousand, five hundred sixty-four".