664440264 has 24 divisors (see below), whose sum is σ = 1799525910. Its totient is φ = 221480064.

The previous prime is 664440263. The next prime is 664440281. The reversal of 664440264 is 462044466.

It is a happy number.

664440264 is a `hidden beast` number, since 6 + 644 + 4 + 0 + 2 + 6 + 4 = 666.

664440264 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 651780900 + 12659364 = 25530^2 + 3558^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (664440263) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4614097 + ... + 4614240.

Almost surely, 2^664440264 is an apocalyptic number.

It is an amenable number.

664440264 is an abundant number, since it is smaller than the sum of its proper divisors (1135085646).

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

664440264 is a wasteful number, since it uses less digits than its factorization.

664440264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9228349 (or 9228342 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 36.

The square root of 664440264 is about 25776.7388162273. The cubic root of 664440264 is about 872.6069092292.

It can be divided in two parts, 6644402 and 64, that added together give a palindrome (6644466).

The spelling of 664440264 in words is "six hundred sixty-four million, four hundred forty thousand, two hundred sixty-four".