405665118 has 64 divisors (see below), whose sum is σ = 957381120. Its totient is φ = 126884736.

The previous prime is 405665107. The next prime is 405665119. The reversal of 405665118 is 811566504.

405665118 is a `hidden beast` number, since 40 + 566 + 51 + 1 + 8 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (405665119) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 593605 + ... + 594287.

It is an arithmetic number, because the mean of its divisors is an integer number (14959080).

Almost surely, 2^405665118 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 405665118, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (478690560).

405665118 is an abundant number, since it is smaller than the sum of its proper divisors (551716002).

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

405665118 is a wasteful number, since it uses less digits than its factorization.

405665118 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1358 (or 1352 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 36.

The square root of 405665118 is about 20141.1300080209. The cubic root of 405665118 is about 740.2684185737.

The spelling of 405665118 in words is "four hundred five million, six hundred sixty-five thousand, one hundred eighteen".