405816 has 32 divisors (see below), whose sum is σ = 1044240. Its totient is φ = 131328.

The previous prime is 405799. The next prime is 405817. The reversal of 405816 is 618504.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (405817) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 660 + ... + 1116.

2⁴⁰⁵⁸¹⁶ 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 405816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (522120).

405816 is an abundant number, since it is smaller than the sum of its proper divisors (638424).

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

405816 is a wasteful number, since it uses less digits than its factorization.

405816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 503 (or 499 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 405816 is about 637.0368906115. The cubic root of 405816 is about 74.0360185017.

It can be divided in two parts, 405 and 816, that added together give a palindrome (1221).

The spelling of 405816 in words is "four hundred five thousand, eight hundred sixteen".