641561361688 has 32 divisors (see below), whose sum is σ = 1299374289360. Its totient is φ = 295210650240.

The previous prime is 641561361677. The next prime is 641561361689. The reversal of 641561361688 is 886163165146.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641561361689) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9284095 + ... + 9352942.

Almost surely, 2^641561361688 is an apocalyptic number.

It is an amenable number.

641561361688 is an abundant number, since it is smaller than the sum of its proper divisors (657812927672).

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

641561361688 is a wasteful number, since it uses less digits than its factorization.

641561361688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18637387 (or 18637383 counting only the distinct ones).

The product of its digits is 4976640, while the sum is 55.

The spelling of 641561361688 in words is "six hundred forty-one billion, five hundred sixty-one million, three hundred sixty-one thousand, six hundred eighty-eight".