405666816 has 176 divisors, whose sum is σ = 1149988224. Its totient is φ = 126959616.

The previous prime is 405666799. The next prime is 405666827. The reversal of 405666816 is 618666504.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4887511 + ... + 4887593.

It is an arithmetic number, because the mean of its divisors is an integer number (6534024).

Almost surely, 2^405666816 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 405666816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (574994112).

405666816 is an abundant number, since it is smaller than the sum of its proper divisors (744321408).

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

405666816 is a wasteful number, since it uses less digits than its factorization.

405666816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 186 (or 168 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 42.

The square root of 405666816 is about 20141.1721605273. The cubic root of 405666816 is about 740.2694514240.

The spelling of 405666816 in words is "four hundred five million, six hundred sixty-six thousand, eight hundred sixteen".