666646575 has 48 divisors (see below), whose sum is σ = 1293726720. Its totient is φ = 296507520.

The previous prime is 666646567. The next prime is 666646601. The reversal of 666646575 is 575646666.

666646575 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 666646575 - 2³ = 666646567 is a prime.

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 47 ways as a sum of consecutive naturals, for example, 2266 + ... + 36584.

It is an arithmetic number, because the mean of its divisors is an integer number (26952640).

Almost surely, 2^666646575 is an apocalyptic number.

666646575 is a deficient number, since it is larger than the sum of its proper divisors (627080145).

666646575 is a wasteful number, since it uses less digits than its factorization.

666646575 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34376 (or 34371 counting only the distinct ones).

The product of its digits is 5443200, while the sum is 51.

The square root of 666646575 is about 25819.4998983327. The cubic root of 666646575 is about 873.5716888044.

Subtracting from 666646575 its reverse (575646666), we obtain a palindrome (90999909).

The spelling of 666646575 in words is "six hundred sixty-six million, six hundred forty-six thousand, five hundred seventy-five".