664666906 has 8 divisors (see below), whose sum is σ = 997264800. Its totient is φ = 332245308.

The previous prime is 664666889. The next prime is 664666913. The reversal of 664666906 is 609666466.

It is a happy number.

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

It is a super-2 number, since 2×664666906² = 883564191863225672, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 664666906.

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, 34206 + ... + 49993.

It is an arithmetic number, because the mean of its divisors is an integer number (124658100).

Almost surely, 2^664666906 is an apocalyptic number.

664666906 is a deficient number, since it is larger than the sum of its proper divisors (332597894).

664666906 is a wasteful number, since it uses less digits than its factorization.

664666906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88148.

The product of its (nonzero) digits is 1679616, while the sum is 49.

The square root of 664666906 is about 25781.1346918634. The cubic root of 664666906 is about 872.7061139803.

The spelling of 664666906 in words is "six hundred sixty-four million, six hundred sixty-six thousand, nine hundred six".