665309705 has 8 divisors (see below), whose sum is σ = 845334792. Its totient is φ = 500939008.

The previous prime is 665309699. The next prime is 665309741. The reversal of 665309705 is 507903566.

665309705 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 7284601 + 658025104 = 2699^2 + 25652^2 .

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 665309705 - 2⁶ = 665309641 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, 3913502 + ... + 3913671.

It is an arithmetic number, because the mean of its divisors is an integer number (105666849).

Almost surely, 2^665309705 is an apocalyptic number.

It is an amenable number.

665309705 is a deficient number, since it is larger than the sum of its proper divisors (180025087).

665309705 is a wasteful number, since it uses less digits than its factorization.

665309705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7827195.

The product of its (nonzero) digits is 170100, while the sum is 41.

The square root of 665309705 is about 25793.5981398486. The cubic root of 665309705 is about 872.9873545385.

The spelling of 665309705 in words is "six hundred sixty-five million, three hundred nine thousand, seven hundred five".