641680781760 has 280 divisors, whose sum is σ = 2284997909040. Its totient is φ = 170932985856.

The previous prime is 641680781723. The next prime is 641680781779. The reversal of 641680781760 is 67187086146.

641680781760 is a `hidden beast` number, since 6 + 416 + 80 + 7 + 81 + 76 + 0 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 641680781697 and 641680781706.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 25311171 + ... + 25336509.

It is an arithmetic number, because the mean of its divisors is an integer number (8160706818).

Almost surely, 2^641680781760 is an apocalyptic number.

641680781760 is a gapful number since it is divisible by the number (60) 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 641680781760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1142498954520).

641680781760 is an abundant number, since it is smaller than the sum of its proper divisors (1643317127280).

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

641680781760 is a wasteful number, since it uses less digits than its factorization.

641680781760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26345 (or 26326 counting only the distinct ones).

The product of its (nonzero) digits is 2709504, while the sum is 54.

The spelling of 641680781760 in words is "six hundred forty-one billion, six hundred eighty million, seven hundred eighty-one thousand, seven hundred sixty".