666311709 has 8 divisors (see below), whose sum is σ = 1015332160. Its totient is φ = 380749536.

The previous prime is 666311689. The next prime is 666311729. The reversal of 666311709 is 907113666.

It is an interprime number because it is at equal distance from previous prime (666311689) and next prime (666311729).

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

It is not a de Polignac number, because 666311709 - 2²⁴ = 649534493 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666311729) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 15864544 + ... + 15864585.

It is an arithmetic number, because the mean of its divisors is an integer number (126916520).

Almost surely, 2^666311709 is an apocalyptic number.

It is an amenable number.

666311709 is a deficient number, since it is larger than the sum of its proper divisors (349020451).

666311709 is a wasteful number, since it uses less digits than its factorization.

666311709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31729139.

The product of its (nonzero) digits is 40824, while the sum is 39.

The square root of 666311709 is about 25813.0143338588. The cubic root of 666311709 is about 873.4253951698.

The spelling of 666311709 in words is "six hundred sixty-six million, three hundred eleven thousand, seven hundred nine".