664045566 has 8 divisors (see below), whose sum is σ = 1328091144. Its totient is φ = 221348520.

The previous prime is 664045561. The next prime is 664045583. The reversal of 664045566 is 665540466.

It is a happy number.

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

664045566 is an admirable number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664045561) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55337125 + ... + 55337136.

It is an arithmetic number, because the mean of its divisors is an integer number (166011393).

Almost surely, 2^664045566 is an apocalyptic number.

664045566 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

664045566 is a wasteful number, since it uses less digits than its factorization.

664045566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110674266.

The product of its (nonzero) digits is 518400, while the sum is 42.

The square root of 664045566 is about 25769.0815901537. The cubic root of 664045566 is about 872.4340898699.

The spelling of 664045566 in words is "six hundred sixty-four million, forty-five thousand, five hundred sixty-six".