666565505 has 8 divisors (see below), whose sum is σ = 841977600. Its totient is φ = 505186416.

The previous prime is 666565499. The next prime is 666565541. The reversal of 666565505 is 505565666.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666565505 is a prime.

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, 3508145 + ... + 3508334.

It is an arithmetic number, because the mean of its divisors is an integer number (105247200).

Almost surely, 2^666565505 is an apocalyptic number.

It is an amenable number.

666565505 is a deficient number, since it is larger than the sum of its proper divisors (175412095).

666565505 is a wasteful number, since it uses less digits than its factorization.

666565505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7016503.

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

The square root of 666565505 is about 25817.9299131437. The cubic root of 666565505 is about 873.5362760732.

The spelling of 666565505 in words is "six hundred sixty-six million, five hundred sixty-five thousand, five hundred five".