665556605 has 32 divisors (see below), whose sum is σ = 963605760. Its totient is φ = 431101440.

The previous prime is 665556601. The next prime is 665556637. The reversal of 665556605 is 506655566.

It is not a de Polignac number, because 665556605 - 2² = 665556601 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665556601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 262745 + ... + 265265.

It is an arithmetic number, because the mean of its divisors is an integer number (30112680).

Almost surely, 2^665556605 is an apocalyptic number.

It is an amenable number.

665556605 is a deficient number, since it is larger than the sum of its proper divisors (298049155).

665556605 is a wasteful number, since it uses less digits than its factorization.

665556605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2949.

The product of its (nonzero) digits is 810000, while the sum is 44.

The square root of 665556605 is about 25798.3837672053. The cubic root of 665556605 is about 873.0953312792.

The spelling of 665556605 in words is "six hundred sixty-five million, five hundred fifty-six thousand, six hundred five".