641681707665 has 8 divisors (see below), whose sum is σ = 1026690732288. Its totient is φ = 342230244080.

The previous prime is 641681707649. The next prime is 641681707669. The reversal of 641681707665 is 566707186146.

641681707665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 641681707665 - 2⁴ = 641681707649 is a prime.

It is not an unprimeable number, because it can be changed into a prime (641681707669) 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, 21389390241 + ... + 21389390270.

It is an arithmetic number, because the mean of its divisors is an integer number (128336341536).

Almost surely, 2^641681707665 is an apocalyptic number.

It is an amenable number.

641681707665 is a deficient number, since it is larger than the sum of its proper divisors (385009024623).

641681707665 is a wasteful number, since it uses less digits than its factorization.

641681707665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42778780519.

The product of its (nonzero) digits is 10160640, while the sum is 57.

The spelling of 641681707665 in words is "six hundred forty-one billion, six hundred eighty-one million, seven hundred seven thousand, six hundred sixty-five".