643345760 has 96 divisors (see below), whose sum is σ = 1574010144. Its totient is φ = 248320000.

The previous prime is 643345753. The next prime is 643345763. The reversal of 643345760 is 67543346.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643345763) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 662075 + ... + 663045.

It is an arithmetic number, because the mean of its divisors is an integer number (16395939).

Almost surely, 2^643345760 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 643345760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (787005072).

643345760 is an abundant number, since it is smaller than the sum of its proper divisors (930664384).

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

643345760 is a wasteful number, since it uses less digits than its factorization.

643345760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1128 (or 1120 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 38.

The square root of 643345760 is about 25364.2614716061. The cubic root of 643345760 is about 863.2729795203.

The spelling of 643345760 in words is "six hundred forty-three million, three hundred forty-five thousand, seven hundred sixty".