643564712 has 64 divisors (see below), whose sum is σ = 1428710400. Its totient is φ = 265950720.

The previous prime is 643564711. The next prime is 643564739. The reversal of 643564712 is 217465346.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (643564711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 674828 + ... + 675780.

It is an arithmetic number, because the mean of its divisors is an integer number (22323600).

Almost surely, 2^643564712 is an apocalyptic number.

643564712 is a gapful number since it is divisible by the number (62) 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 643564712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (714355200).

643564712 is an abundant number, since it is smaller than the sum of its proper divisors (785145688).

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

643564712 is a wasteful number, since it uses less digits than its factorization.

643564712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1386 (or 1382 counting only the distinct ones).

The product of its digits is 120960, while the sum is 38.

The square root of 643564712 is about 25368.5772561253. The cubic root of 643564712 is about 863.3709019328.

The spelling of 643564712 in words is "six hundred forty-three million, five hundred sixty-four thousand, seven hundred twelve".