641708784 has 80 divisors (see below), whose sum is σ = 1865356800. Its totient is φ = 211184064.

The previous prime is 641708783. The next prime is 641708801. The reversal of 641708784 is 487807146.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641708783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24727 + ... + 43529.

It is an arithmetic number, because the mean of its divisors is an integer number (23316960).

Almost surely, 2^641708784 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 641708784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (932678400).

641708784 is an abundant number, since it is smaller than the sum of its proper divisors (1223648016).

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

641708784 is a wasteful number, since it uses less digits than its factorization.

641708784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18899 (or 18887 counting only the distinct ones).

The product of its (nonzero) digits is 301056, while the sum is 45.

The square root of 641708784 is about 25331.9715774355. The cubic root of 641708784 is about 862.5401659934.

The spelling of 641708784 in words is "six hundred forty-one million, seven hundred eight thousand, seven hundred eighty-four".