666665605 has 8 divisors (see below), whose sum is σ = 800935200. Its totient is φ = 532708176.

The previous prime is 666665569. The next prime is 666665621. The reversal of 666665605 is 506566666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 666665605 - 2⁹ = 666665093 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 73315 + ... + 81904.

It is an arithmetic number, because the mean of its divisors is an integer number (100116900).

Almost surely, 2^666665605 is an apocalyptic number.

It is an amenable number.

666665605 is a deficient number, since it is larger than the sum of its proper divisors (134269595).

666665605 is a wasteful number, since it uses less digits than its factorization.

666665605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156083.

The product of its (nonzero) digits is 1166400, while the sum is 46.

The square root of 666665605 is about 25819.8684156213. The cubic root of 666665605 is about 873.5800010104.

The spelling of 666665605 in words is "six hundred sixty-six million, six hundred sixty-five thousand, six hundred five".