664676666 has 8 divisors (see below), whose sum is σ = 1021332564. Its totient is φ = 324232480.

The previous prime is 664676651. The next prime is 664676711. The reversal of 664676666 is 666676466.

It can be written as a sum of positive squares in 2 ways, for example, as 664350625 + 326041 = 25775^2 + 571^2 .

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

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, 4052825 + ... + 4052988.

Almost surely, 2^664676666 is an apocalyptic number.

664676666 is a deficient number, since it is larger than the sum of its proper divisors (356655898).

664676666 is a wasteful number, since it uses less digits than its factorization.

664676666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8105856.

The product of its digits is 7838208, while the sum is 53.

The square root of 664676666 is about 25781.3239768636. The cubic root of 664676666 is about 872.7103855785.

The spelling of 664676666 in words is "six hundred sixty-four million, six hundred seventy-six thousand, six hundred sixty-six".