664430256 has 320 divisors, whose sum is σ = 2339850240. Its totient is φ = 176394240.

The previous prime is 664430243. The next prime is 664430287. The reversal of 664430256 is 652034466.

664430256 is a `hidden beast` number, since 6 + 644 + 3 + 0 + 2 + 5 + 6 = 666.

664430256 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-4 number, since 4×664430256⁴ (a number of 36 digits) contains 4444 as substring.

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

It is a self number, because there is not a number n which added to its sum of digits gives 664430256.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2851516 + ... + 2851748.

It is an arithmetic number, because the mean of its divisors is an integer number (7312032).

Almost surely, 2^664430256 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 664430256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1169925120).

664430256 is an abundant number, since it is smaller than the sum of its proper divisors (1675419984).

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

664430256 is a wasteful number, since it uses less digits than its factorization.

664430256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321 (or 309 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 36.

The square root of 664430256 is about 25776.5446869824. The cubic root of 664430256 is about 872.6025280510.

The spelling of 664430256 in words is "six hundred sixty-four million, four hundred thirty thousand, two hundred fifty-six".