664420614400 has 243 divisors, whose sum is σ = 1723045038589. Its totient is φ = 253639260160.

The previous prime is 664420614383. The next prime is 664420614409. The reversal of 664420614400 is 4416024466.

The square root of 664420614400 is 815120.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 239191421184 + 425229193216 = 489072^2 + 652096^2 .

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 664420614400.

It is not an unprimeable number, because it can be changed into a prime (664420614409) by changing a digit.

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 26 ways as a sum of consecutive naturals, for example, 1499820579 + ... + 1499821021.

Almost surely, 2^664420614400 is an apocalyptic number.

664420614400 is the 815120-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664420614400

664420614400 is an abundant number, since it is smaller than the sum of its proper divisors (1058624424189).

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

664420614400 is an frugal number, since it uses more digits than its factorization.

664420614400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 958 (or 473 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 37.

Adding to 664420614400 its reverse (4416024466), we get a palindrome (668836638866).

The spelling of 664420614400 in words is "six hundred sixty-four billion, four hundred twenty million, six hundred fourteen thousand, four hundred".