664600666 has 8 divisors (see below), whose sum is σ = 997678260. Its totient is φ = 332041248.

The previous prime is 664600637. The next prime is 664600751. The reversal of 664600666 is 666006466.

It can be written as a sum of positive squares in 2 ways, for example, as 657153225 + 7447441 = 25635^2 + 2729^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 126321 + ... + 131476.

Almost surely, 2^664600666 is an apocalyptic number.

664600666 is a deficient number, since it is larger than the sum of its proper divisors (333077594).

664600666 is a wasteful number, since it uses less digits than its factorization.

664600666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 259088.

The product of its (nonzero) digits is 186624, while the sum is 40.

The square root of 664600666 is about 25779.8499995636. The cubic root of 664600666 is about 872.6771220281.

The spelling of 664600666 in words is "six hundred sixty-four million, six hundred thousand, six hundred sixty-six".