320644656 has 200 divisors, whose sum is σ = 1002507264. Its totient is φ = 98651520.

The previous prime is 320644651. The next prime is 320644657. The reversal of 320644656 is 656446023.

320644656 is a `hidden beast` number, since 3 + 2 + 0 + 644 + 6 + 5 + 6 = 666.

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 320644656.

It is not an unprimeable number, because it can be changed into a prime (320644651) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 923875 + ... + 924221.

Almost surely, 2^320644656 is an apocalyptic number.

320644656 is a gapful number since it is divisible by the number (36) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 320644656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (501253632).

320644656 is an abundant number, since it is smaller than the sum of its proper divisors (681862608).

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

320644656 is a wasteful number, since it uses less digits than its factorization.

320644656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 421 (or 406 counting only the distinct ones).

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

The square root of 320644656 is about 17906.5534372196. The cubic root of 320644656 is about 684.4493815196.

The spelling of 320644656 in words is "three hundred twenty million, six hundred forty-four thousand, six hundred fifty-six".