664440000 has 420 divisors, whose sum is σ = 2578068504. Its totient is φ = 150528000.

The previous prime is 664439989. The next prime is 664440037. The reversal of 664440000 is 44466.

It is a tau number, because it is divible by the number of its divisors (420).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a nialpdrome in base 10.

It is a zygodrome 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 59 ways as a sum of consecutive naturals, for example, 5879944 + ... + 5880056.

Almost surely, 2^664440000 is an apocalyptic number.

664440000 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664440000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1289034252).

664440000 is an abundant number, since it is smaller than the sum of its proper divisors (1913628504).

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

664440000 is a wasteful number, since it uses less digits than its factorization.

664440000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162 (or 130 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 24.

The square root of 664440000 is about 25776.7336953308. The cubic root of 664440000 is about 872.6067936592.

Adding to 664440000 its reverse (44466), we get a palindrome (664484466).

The spelling of 664440000 in words is "six hundred sixty-four million, four hundred forty thousand".