405824 has 28 divisors (see below), whose sum is σ = 854964. Its totient is φ = 190464.

The previous prime is 405817. The next prime is 405827. The reversal of 405824 is 428504.

It can be written as a sum of positive squares in 2 ways, for example, as 270400 + 135424 = 520^2 + 368^2 .

It is a hoax number, since the sum of its digits (23) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 405824.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (405827) by changing a digit.

405824 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 3 ways as a sum of consecutive naturals, for example, 902 + ... + 1274.

2⁴⁰⁵⁸²⁴ 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 405824, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (427482).

405824 is an abundant number, since it is smaller than the sum of its proper divisors (449140).

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

405824 is a wasteful number, since it uses less digits than its factorization.

405824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 402 (or 392 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 23.

The square root of 405824 is about 637.0431696518. The cubic root of 405824 is about 74.0365049982.

The spelling of 405824 in words is "four hundred five thousand, eight hundred twenty-four".