Is 641 a prime number?
It is possible to find out using mathematical methods whether a given integer is a prime number or not.
For 641, the answer is: yes, 641 is a prime number because it has only two distinct divisors: 1 and itself (641).
As a consequence, 641 is only a multiple of 1 and 641.
Find out more:
Since 641 is a prime number, 641 is also a deficient number, that is to say 641 is a natural integer that is strictly larger than the sum of its proper divisors, i.e., the divisors of 641 without 641 itself (that is 1, by definition!).