641645824 has 72 divisors (see below), whose sum is σ = 1378927368. Its totient is φ = 296878080.

The previous prime is 641645803. The next prime is 641645839. The reversal of 641645824 is 428546146.

It can be written as a sum of positive squares in 4 ways, for example, as 175085824 + 466560000 = 13232^2 + 21600^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 264264 + ... + 266680.

It is an arithmetic number, because the mean of its divisors is an integer number (19151769).

Almost surely, 2^641645824 is an apocalyptic number.

641645824 is a gapful number since it is divisible by the number (64) 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 641645824, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (689463684).

641645824 is an abundant number, since it is smaller than the sum of its proper divisors (737281544).

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

641645824 is a wasteful number, since it uses less digits than its factorization.

641645824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2511 (or 2497 counting only the distinct ones).

The product of its digits is 184320, while the sum is 40.

The square root of 641645824 is about 25330.7288485744. The cubic root of 641645824 is about 862.5119562580.

The spelling of 641645824 in words is "six hundred forty-one million, six hundred forty-five thousand, eight hundred twenty-four".