664121200 has 60 divisors (see below), whose sum is σ = 1607330160. Its totient is φ = 263687680.

The previous prime is 664121189. The next prime is 664121203. The reversal of 664121200 is 2121466.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664121203) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 48741 + ... + 60859.

It is an arithmetic number, because the mean of its divisors is an integer number (26788836).

Almost surely, 2^664121200 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 664121200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (803665080).

664121200 is an abundant number, since it is smaller than the sum of its proper divisors (943208960).

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

664121200 is a wasteful number, since it uses less digits than its factorization.

664121200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12274 (or 12263 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 664121200 is about 25770.5490822373. The cubic root of 664121200 is about 872.4672116807.

Adding to 664121200 its reverse (2121466), we get a palindrome (666242666).

The spelling of 664121200 in words is "six hundred sixty-four million, one hundred twenty-one thousand, two hundred".