It is possible to find out using mathematical methods whether a given integer is a prime number or not.
Yes, 166 848 881 is a prime number.
Indeed, the definition of a prime numbers is to have exactly two distinct positive divisors, 1 and itself. A number is a divisor of another number when the remainder of Euclid’s division of the second one by the first one is zero. Concerning the number 166 848 881, the only two divisors are 1 and 166 848 881. Therefore 166 848 881 is a prime number.
Find out more:
Since 166848881 is a prime number, 166848881 is also a deficient number, that is to say 166848881 is a natural integer that is strictly larger than the sum of its proper divisors, i.e., the divisors of 166848881 without 166848881 itself (that is 1, by definition!).