664205120 has 28 divisors (see below), whose sum is σ = 1581639204. Its totient is φ = 265681920.

The previous prime is 664205099. The next prime is 664205123. The reversal of 664205120 is 21502466.

It can be written as a sum of positive squares in 2 ways, for example, as 250652224 + 413552896 = 15832^2 + 20336^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 664205120.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664205123) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1037501 + ... + 1038140.

Almost surely, 2^664205120 is an apocalyptic number.

It is an amenable number.

664205120 is an abundant number, since it is smaller than the sum of its proper divisors (917434084).

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

664205120 is a wasteful number, since it uses less digits than its factorization.

664205120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2075658 (or 2075648 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 664205120 is about 25772.1772460147. The cubic root of 664205120 is about 872.5039591723.

Adding to 664205120 its reverse (21502466), we get a palindrome (685707586).

The spelling of 664205120 in words is "six hundred sixty-four million, two hundred five thousand, one hundred twenty".