664012566 has 72 divisors (see below), whose sum is σ = 1707610320. Its totient is φ = 189691632.

The previous prime is 664012549. The next prime is 664012577. The reversal of 664012566 is 665210466.

It is a happy number.

664012566 is a `hidden beast` number, since 6 + 640 + 1 + 2 + 5 + 6 + 6 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 664012566.

It is a congruent number.

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 35 ways as a sum of consecutive naturals, for example, 88240 + ... + 95468.

It is an arithmetic number, because the mean of its divisors is an integer number (23716810).

Almost surely, 2^664012566 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664012566, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (853805160).

664012566 is an abundant number, since it is smaller than the sum of its proper divisors (1043597754).

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

664012566 is an frugal number, since it uses more digits than its factorization.

664012566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7262 (or 7241 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 664012566 is about 25768.4412799843. The cubic root of 664012566 is about 872.4196376478.

The spelling of 664012566 in words is "six hundred sixty-four million, twelve thousand, five hundred sixty-six".