665055405 has 96 divisors (see below), whose sum is σ = 1392768000. Its totient is φ = 287110656.

The previous prime is 665055401. The next prime is 665055421. The reversal of 665055405 is 504550566.

It is a happy number.

665055405 is a `hidden beast` number, since 66 + 50 + 5 + 540 + 5 = 666.

It is not a de Polignac number, because 665055405 - 2² = 665055401 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 665055405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665055401) 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 95 ways as a sum of consecutive naturals, for example, 428571 + ... + 430119.

It is an arithmetic number, because the mean of its divisors is an integer number (14508000).

Almost surely, 2^665055405 is an apocalyptic number.

It is an amenable number.

665055405 is an abundant number, since it is smaller than the sum of its proper divisors (727712595).

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

665055405 is a wasteful number, since it uses less digits than its factorization.

665055405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1643 (or 1640 counting only the distinct ones).

The product of its (nonzero) digits is 90000, while the sum is 36.

The square root of 665055405 is about 25788.6681509534. The cubic root of 665055405 is about 872.8761136264.

The spelling of 665055405 in words is "six hundred sixty-five million, fifty-five thousand, four hundred five".