664661000 has 32 divisors (see below), whose sum is σ = 1555309080. Its totient is φ = 265864000.

The previous prime is 664660999. The next prime is 664661029. The reversal of 664661000 is 166466.

664661000 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 299774596 + 364886404 = 17314^2 + 19102^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 331331 + ... + 333330.

Almost surely, 2^664661000 is an apocalyptic number.

It is an amenable number.

664661000 is an abundant number, since it is smaller than the sum of its proper divisors (890648080).

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

664661000 is a wasteful number, since it uses less digits than its factorization.

664661000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 664682 (or 664668 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 664661000 is about 25781.0201504906. The cubic root of 664661000 is about 872.7035291178.

The spelling of 664661000 in words is "six hundred sixty-four million, six hundred sixty-one thousand".