664001000 has 96 divisors (see below), whose sum is σ = 1682904600. Its totient is φ = 245107200.

The previous prime is 664000979. The next prime is 664001047. The reversal of 664001000 is 100466.

It can be written as a sum of positive squares in 12 ways, for example, as 343805764 + 320195236 = 18542^2 + 17894^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 664001000.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 167036 + ... + 170964.

Almost surely, 2^664001000 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664001000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (841452300).

664001000 is an abundant number, since it is smaller than the sum of its proper divisors (1018903600).

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

664001000 is a wasteful number, since it uses less digits than its factorization.

664001000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3976 (or 3949 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 664001000 is about 25768.2168572061. The cubic root of 664001000 is about 872.4145722497.

Adding to 664001000 its reverse (100466), we get a palindrome (664101466).

The spelling of 664001000 in words is "six hundred sixty-four million, one thousand".