641517531768 has 160 divisors (see below), whose sum is σ = 1856021439360. Its totient is φ = 206805519360.

The previous prime is 641517531751. The next prime is 641517531793. The reversal of 641517531768 is 867135715146.

641517531768 is a `hidden beast` number, since 6 + 4 + 1 + 517 + 53 + 1 + 76 + 8 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 33276180 + ... + 33295452.

It is an arithmetic number, because the mean of its divisors is an integer number (11600133996).

Almost surely, 2^641517531768 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 641517531768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (928010719680).

641517531768 is an abundant number, since it is smaller than the sum of its proper divisors (1214503907592).

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

641517531768 is a wasteful number, since it uses less digits than its factorization.

641517531768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20979 (or 20966 counting only the distinct ones).

The product of its digits is 4233600, while the sum is 54.

The spelling of 641517531768 in words is "six hundred forty-one billion, five hundred seventeen million, five hundred thirty-one thousand, seven hundred sixty-eight".