666102785 has 4 divisors (see below), whose sum is σ = 799323348. Its totient is φ = 532882224.

The previous prime is 666102763. The next prime is 666102841. The reversal of 666102785 is 587201666.

666102785 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 315701824 + 350400961 = 17768^2 + 18719^2 .

It is a cyclic number.

It is not a de Polignac number, because 666102785 - 2²⁶ = 598993921 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 3 ways as a sum of consecutive naturals, for example, 66610274 + ... + 66610283.

It is an arithmetic number, because the mean of its divisors is an integer number (199830837).

Almost surely, 2^666102785 is an apocalyptic number.

It is an amenable number.

666102785 is a deficient number, since it is larger than the sum of its proper divisors (133220563).

666102785 is a wasteful number, since it uses less digits than its factorization.

666102785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133220562.

The product of its (nonzero) digits is 120960, while the sum is 41.

The square root of 666102785 is about 25808.9671432237. The cubic root of 666102785 is about 873.3340972580.

The spelling of 666102785 in words is "six hundred sixty-six million, one hundred two thousand, seven hundred eighty-five".