666650565 has 24 divisors (see below), whose sum is σ = 1320603648. Its totient is φ = 304754400.

The previous prime is 666650557. The next prime is 666650599. The reversal of 666650565 is 565056666.

It is not a de Polignac number, because 666650565 - 2³ = 666650557 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 666650565.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 1057861 + ... + 1058490.

It is an arithmetic number, because the mean of its divisors is an integer number (55025152).

Almost surely, 2^666650565 is an apocalyptic number.

It is an amenable number.

666650565 is a deficient number, since it is larger than the sum of its proper divisors (653953083).

666650565 is a wasteful number, since it uses less digits than its factorization.

666650565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2116369 (or 2116366 counting only the distinct ones).

The product of its (nonzero) digits is 972000, while the sum is 45.

The square root of 666650565 is about 25819.5771653991. The cubic root of 666650565 is about 873.5734316290.

The spelling of 666650565 in words is "six hundred sixty-six million, six hundred fifty thousand, five hundred sixty-five".