666785 has 8 divisors (see below), whose sum is σ = 914496. Its totient is φ = 457200.

The previous prime is 666773. The next prime is 666811. The reversal of 666785 is 587666.

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

It is not a de Polignac number, because 666785 - 2⁴ = 666769 is a prime.

It is a Duffinian number.

It is a Curzon 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, 9491 + ... + 9560.

It is an arithmetic number, because the mean of its divisors is an integer number (114312).

2⁶⁶⁶⁷⁸⁵ is an apocalyptic number.

It is an amenable number.

666785 is a deficient number, since it is larger than the sum of its proper divisors (247711).

666785 is a wasteful number, since it uses less digits than its factorization.

666785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19063.

The product of its digits is 60480, while the sum is 38.

The square root of 666785 is about 816.5690417840. The cubic root of 666785 is about 87.3632148523.

The spelling of 666785 in words is "six hundred sixty-six thousand, seven hundred eighty-five".