666354385 has 4 divisors (see below), whose sum is σ = 799625268. Its totient is φ = 533083504.

The previous prime is 666354379. The next prime is 666354397. The reversal of 666354385 is 583453666.

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 506610064 + 159744321 = 22508^2 + 12639^2 .

It is a cyclic number.

It is not a de Polignac number, because 666354385 - 2⁹ = 666353873 is a prime.

It is a Duffinian 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 3 ways as a sum of consecutive naturals, for example, 66635434 + ... + 66635443.

It is an arithmetic number, because the mean of its divisors is an integer number (199906317).

Almost surely, 2^666354385 is an apocalyptic number.

It is an amenable number.

666354385 is a deficient number, since it is larger than the sum of its proper divisors (133270883).

666354385 is a wasteful number, since it uses less digits than its factorization.

666354385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133270882.

The product of its digits is 1555200, while the sum is 46.

The square root of 666354385 is about 25813.8409579047. The cubic root of 666354385 is about 873.4440418512. Note that the first 3 decimals are identical.

The spelling of 666354385 in words is "six hundred sixty-six million, three hundred fifty-four thousand, three hundred eighty-five".