664973971200 has 1728 divisors, whose sum is σ = 3082592701440. Its totient is φ = 137952460800.

The previous prime is 664973971163. The next prime is 664973971243. The reversal of 664973971200 is 2179379466.

It is a happy number.

664973971200 is a `hidden beast` number, since 6 + 6 + 49 + 7 + 397 + 1 + 200 = 666.

It is a tau number, because it is divible by the number of its divisors (1728).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

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 191 ways as a sum of consecutive naturals, for example, 1077753292 + ... + 1077753908.

Almost surely, 2^664973971200 is an apocalyptic number.

664973971200 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 664973971200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1541296350720).

664973971200 is an abundant number, since it is smaller than the sum of its proper divisors (2417618730240).

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

664973971200 is an equidigital number, since it uses as much as digits as its factorization.

664973971200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 682 (or 645 counting only the distinct ones).

The product of its (nonzero) digits is 3429216, while the sum is 54.

The spelling of 664973971200 in words is "six hundred sixty-four billion, nine hundred seventy-three million, nine hundred seventy-one thousand, two hundred".