664442000 has 40 divisors (see below), whose sum is σ = 1606625592. Its totient is φ = 265776000.

The previous prime is 664441931. The next prime is 664442021. The reversal of 664442000 is 244466.

It can be written as a sum of positive squares in 4 ways, for example, as 246016 + 664195984 = 496^2 + 25772^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a nialpdrome in base 10.

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 7 ways as a sum of consecutive naturals, for example, 164111 + ... + 168110.

Almost surely, 2^664442000 is an apocalyptic number.

It is an amenable number.

664442000 is an abundant number, since it is smaller than the sum of its proper divisors (942183592).

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

664442000 is a wasteful number, since it uses less digits than its factorization.

664442000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 332244 (or 332228 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 26.

The square root of 664442000 is about 25776.7724899763. The cubic root of 664442000 is about 872.6076691894.

Adding to 664442000 its reverse (244466), we get a palindrome (664686466).

The spelling of 664442000 in words is "six hundred sixty-four million, four hundred forty-two thousand".