405378666 has 192 divisors, whose sum is σ = 1150156800. Its totient is φ = 102241440.

The previous prime is 405378653. The next prime is 405378667. The reversal of 405378666 is 666873504.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (405378667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3191895 + ... + 3192021.

It is an arithmetic number, because the mean of its divisors is an integer number (5990400).

Almost surely, 2^405378666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 405378666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (575078400).

405378666 is an abundant number, since it is smaller than the sum of its proper divisors (744778134).

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

405378666 is a wasteful number, since it uses less digits than its factorization.

405378666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214 (or 197 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 45.

The square root of 405378666 is about 20134.0176318588. The cubic root of 405378666 is about 740.0941358209.

The spelling of 405378666 in words is "four hundred five million, three hundred seventy-eight thousand, six hundred sixty-six".