643748688 has 80 divisors (see below), whose sum is σ = 2015793600. Its totient is φ = 195073920.

The previous prime is 643748687. The next prime is 643748713. The reversal of 643748688 is 886847346.

643748688 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643748687) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 62983 + ... + 72486.

It is an arithmetic number, because the mean of its divisors is an integer number (25197420).

Almost surely, 2^643748688 is an apocalyptic number.

It is an amenable number.

643748688 is an abundant number, since it is smaller than the sum of its proper divisors (1372044912).

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

643748688 is a wasteful number, since it uses less digits than its factorization.

643748688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135497 (or 135485 counting only the distinct ones).

The product of its digits is 6193152, while the sum is 54.

The square root of 643748688 is about 25372.2030576771. The cubic root of 643748688 is about 863.4531647774.

The spelling of 643748688 in words is "six hundred forty-three million, seven hundred forty-eight thousand, six hundred eighty-eight".