641805279808 has 112 divisors (see below), whose sum is σ = 1593018814464. Its totient is φ = 249238909440.

The previous prime is 641805279803. The next prime is 641805279853. The reversal of 641805279808 is 808972508146.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (112).

It is not an unprimeable number, because it can be changed into a prime (641805279803) 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, 1300785 + ... + 1725007.

It is an arithmetic number, because the mean of its divisors is an integer number (14223382272).

Almost surely, 2^641805279808 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 641805279808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (796509407232).

641805279808 is an abundant number, since it is smaller than the sum of its proper divisors (951213534656).

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

641805279808 is a wasteful number, since it uses less digits than its factorization.

641805279808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 424560 (or 424550 counting only the distinct ones).

The product of its (nonzero) digits is 7741440, while the sum is 58.

The spelling of 641805279808 in words is "six hundred forty-one billion, eight hundred five million, two hundred seventy-nine thousand, eight hundred eight".